ALTERNATOR 2007 Ford Pickup 6.0L Eng F350 Super Duty REQUESTED INFORMATION Vehicles With Dual Generator [ Engine Mount - LH ] Fig 1: Rotating Drive Belt Tensioner Clockwise 1. Remove the accessory drive belt. Fig 2: Locating Accessory Drive Belt Tensioner Bolt 2. Remove the bolt and the accessory drive belt tensioner. 1. To install, tighten to 25 Nm (18 lb-ft). http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 1/110
Fig 3: Rotating Accessory Drive Belt Tensioner 3. Remove the accessory drive belt. Fig 4: Locating Bracket And Accessory Drive Belt Idler Pulley Bolts 4. Remove the bolts, bracket and the accessory drive belt idler pulley. 1. To install, tighten to 25 Nm (18 lb-ft). Fig 5: Locating Accessory Drive Belt Tensioner Bolts 5. Remove the bolts and the accessory drive belt tensioner. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 2/110
1. To install, tighten to 25 Nm (18 lb-ft). Fig 6: Locating Wire Retainer And Generator Electrical Connectors 6. Disconnect the wire retainer, generator electrical connector and B+ wire. 1. To install, tighten to 8 Nm (71 lb-in). Fig 7: Identifying Generator Mounting Bracket Bolts 7. Remove the bolts and generator with mounting bracket. 1. To install, tighten to 47 Nm (35 lb-ft). Vehicles With Dual Generator [ Engine Mount - RH ] http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 3/110
Fig 8: Rotating Drive Belt Tensioner Clockwise 1. Remove the accessory drive belt. Fig 9: Locating Accessory Drive Belt Tensioner Bolt 2. Remove the bolt and the accessory drive belt tensioner. 1. To install, tighten to 25 Nm (18 lb-ft). Fig 10: Rotating Accessory Drive Belt Tensioner 3. Remove the accessory drive belt. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 4/110
Fig 11: Locating Bracket And Accessory Drive Belt Idler Pulley Bolts 4. Remove the bolts, bracket and the accessory drive belt idler pulley. 1. To install, tighten to 25 Nm (18 lb-ft). Fig 12: Locating Accessory Drive Belt Tensioner Bolts 5. Remove the bolts and the accessory drive belt tensioner. 1. To install, tighten to 25 Nm (18 lb-ft). Fig 13: Locating Wire Retainer And Generator Electrical Connectors http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 5/110
6. Disconnect the wire retainer, generator electrical connector and B+ wire. 1. To install, tighten to 8 Nm (71 lb-in). Fig 14: Identifying Generator Mounting Bracket Bolts 7. Remove the bolts and generator with mounting bracket. 1. To install, tighten to 47 Nm (35 lb-ft). Vehicles With Single Generator [ Engine Mount - RH ] Fig 15: Rotating Accessory Drive Belt Tensioner 1. Remove the primary accessory drive belt. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 6/110
Fig 16: Locating Accessory Drive Belt Tensioner Bolts 2. Remove the bolts and the accessory drive belt tensioner. 1. To install, tighten to 25 Nm (18 lb-ft). Vehicles With Single Generator [ Engine Mount - LH ] Fig 17: Rotating Accessory Drive Belt Tensioner 1. Remove the primary accessory drive belt. Fig 18: Locating Accessory Drive Belt Tensioner Bolts http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 7/110
2. Remove the bolts and the accessory drive belt tensioner. 1. To install, tighten to 25 Nm (18 lb-ft). Vehicles With Dual Generator [ REMOVAL ] Fig 19: Rotating Drive Belt Tensioner Clockwise 1. Rotate the tensioner clockwise and remove the dual generator accessory drive belt. 2. Remove the 3 bolts and the dual generator pulley. Vehicles With Dual Generators [ Intake Manifold : REMOVAL ] Fig 20: Rotating Drive Belt Tensioner Clockwise 1. Remove the accessory drive belt. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 8/110
Fig 21: Locating Accessory Drive Belt Tensioner Bolt 2. Remove the bolt and the accessory drive belt tensioner. Fig 22: Rotating Accessory Drive Belt Tensioner 3. Remove the accessory drive belt. Fig 23: Locating Bracket And Accessory Drive Belt Idler Pulley Bolts 4. Remove the bolts, bracket and accessory drive belt idler pulley. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 9/110
Fig 24: Locating Accessory Drive Belt Tensioner Bolts 5. Remove the bolts and the accessory drive belt tensioner. Fig 25: Locating Wire Retainer And Generator Electrical Connectors 6. Disconnect the wiring harness retainer, generator electrical connector and B+ wire. Fig 26: Identifying Generator Mounting Bracket Bolts 7. Remove the bolts and the generator with mounting bracket. Vehicles With Dual Generators [ Material : REMOVAL ] http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 10/110
Fig 27: Rotating Drive Belt Tensioner Clockwise 1. Remove the secondary accessory drive belt. Fig 28: Locating Accessory Drive Belt Tensioner Bolt 2. Remove the bolt and the secondary accessory drive belt tensioner. Fig 29: Rotating Accessory Drive Belt Tensioner 3. Remove the primary accessory drive belt. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 11/110
Fig 30: Locating Bracket And Accessory Drive Belt Idler Pulley Bolts 4. Remove the bolts, bracket and secondary accessory drive belt idler pulley. Fig 31: Locating Accessory Drive Belt Tensioner Bolts 5. Remove the bolts and the primary accessory drive belt tensioner. Fig 32: Locating Wire Retainer And Generator Electrical Connectors 6. Disconnect the wire retainer, secondary generator electrical connector and B+ wire. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 12/110
Fig 33: Identifying Generator Mounting Bracket Bolts 7. Remove the bolts and the secondary generator with mounting bracket. Vehicles With Single Generator [ Material : REMOVAL ] Fig 34: Rotating Accessory Drive Belt Tensioner 1. Remove the primary accessory drive belt. Fig 35: Locating Accessory Drive Belt Tensioner Bolts http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 13/110
2. Remove the bolts and the primary accessory drive belt tensioner. Vehicles With Single Generator [ Intake Manifold : REMOVAL ] Fig 36: Rotating Accessory Drive Belt Tensioner 1. Remove the accessory drive belt. Charging System - Dual Generators Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105- R0057 or equivalent SABRE Premium Electrical System Tester 010-00736 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 14/110
Flex Probe Kit 105- R025B Micro 490 Digital Battery Analyzer 162-00004 or equivalent Principles Of Operation With the key in the ON position (dual generator system), voltage is supplied by the powertrain control module (PCM)-controlled I circuit 1183 (WH/YE) / 904 (LG/RD) to the upper generator and through the I circuit 1185 (YE) to the lower generator. If the glow plug system is not cycling, the PCM maintains power to the lower generator. If the glow plug system is cycling, the PCM supplies power to the lower generator momentarily to verify there is a volt drop, then shuts off the power on the lower generator I circuit 1185 (YE). Once the glow plug system stops cycling, the PCM supplies power on the lower generator I circuit 1185 (YE), which turns the regulator on allowing current to flow from the battery sense A circuit to the generator field coil, at which time it begins to function normally. The PCM maintains power on the upper generator I circuit 1183 (WH/YE) / 904 (LG/RD), which turns on the regulator, allowing current to flow from the battery sense A circuit to the generator field coil. Once the generator begins generating current, a voltage signal is taken from the generator stator and fed back to the regulator internally. This voltage feedback signal (typically one-half of the battery voltage) is used by the PCM to turn off the charging system warning indicator. With the system functioning normally, the generator output current is determined by the voltage of the A circuit 35 (OG/LB). The A circuit 35 (OG/LB) voltage is compared to a set voltage internal to the regulator, and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. This allows for more efficient battery recharge in the winter and reduces the chance of overcharging in the summer. Circuit Description Positive Battery Output (B+) Circuit 1119 (RD) (Upper) / Circuit 36 (YE/WH) (Lower) The generator output is supplied through the positive battery output (B+) terminal on the rear of the generator to the battery and the electrical system. I Circuit - Dual Generator The I (ignition) circuit is used to turn on the voltage regulator(s). This circuit is powered up when the key is in the ON position. When the PCM detects key ON, the PCM provides power to the http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 15/110
upper generator I circuit 1183 (WH/YE) / 904 (LG/RD) and also to the lower generator I circuit 1185 (YE). The power to the lower generator is only momentary unless the glow plug system is not cycling. Once the glow plugs stop cycling, the PCM provides constant power on the lower generator I circuit 1185 (YE). A Circuit 35 (OG/LB) The A circuit or battery sense circuit is used to sense battery voltage. This voltage is used by the regulator to determine generator output. Inspection And Verification WARNING: Batteries contain sulfuric acid. Avoid contact with skin, eyes or clothing. Also, shield your eyes when working near batteries to protect against possible splashing of the acid solution. In case of acid contact with skin or eyes, flush immediately with water for a minimum of 15 minutes and get prompt medical attention. If acid is swallowed, call a physician immediately. Failure to follow these instructions may result in personal injury. WARNING: Batteries normally produce explosive gases. Therefore, do not allow flames, sparks or lighted substances to come near the battery. When charging or working near a battery, always shield your face and protect your eyes. Always provide ventilation. Failure to follow these instructions may result in personal injury. WARNING: When lifting a battery, excessive pressure on the end walls could cause acid to spew through the vent caps, resulting in personal injury, damage to the vehicle or battery. Lift with a battery carrier or with your hands on opposite corners. Failure to follow these instructions may result in personal injury. CAUTION: Do not make jumper connections except as directed. Incorrect connections may damage the voltage regulator http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 16/110
test terminals, fuses, or fusible links. CAUTION: Do not allow any metal object to come in contact with the generator housing and internal diode cooling fins. A short circuit may result and burn out the diodes. NOTE: While carrying out any pinpoint test, disregard the diagnostic trouble codes (DTCs) set while following the specific pinpoint test. After the completion of any test, be sure to clear all DTCs in the PCM. NOTE: All voltage measurements are referenced to the negative (-) battery post unless otherwise specified. NOTE: The dual generator I circuit/bulb circuit 4-way connector MUST be connected before disconnecting or connecting the battery. The PCM relearns its parameters every time it is disconnected and connected to power. Failure to follow this procedure causes the PCM to misinterpret the charging system as a single generator system, causing loss of DTC capability and control. 1. Verify the customer concern. 2. Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical 1. Battery 2. Generator drive belt 3. Generator pulley 1. Charging system warning indicator 2. Circuitry 3. Cables 3. If an obvious cause for an observed or reported concern is found, correct the cause (if http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 17/110
possible) before proceeding to the next step. 4. Verify the battery condition. Refer to BATTERY, MOUNTING AND CABLES article. 5. Check the operation of the charging system warning indicator in the instrument cluster (IC) as follows: 1. With the key in the OFF position, the charging system warning indicator should be off. 1. With the key in the ON position and the engine off, the charging system warning indicator should be on. 1. With the engine running, the charging system warning indicator should be off. NOTE: The PCM requires 3 key cycles to re-learn the configuration. NOTE: On California vehicles, the malfunction indicator lamp (MIL) illuminates if the lower generator circuit has 12 volts (which the PCM has commanded off) for 2 consecutive drive cycles. NOTE: When testing the I circuit with the engine running, make certain to load the charging system by turning the blower motor to the HIGH position and the headlamps on high beam. 6. Check the battery voltage before and after starting the engine to determine if the battery voltage increases. Refer to the Normal Charging System Voltages chart. NORMAL CHARGING SYSTEM VOLTAGES Ignition Key Position A Circuit 35 (OG/LB) I Circuit 904 (LG/RD) (Upper), Circuit 1185 (YE) (Lower) Generator B+ Circuit 1119 (RD) (Upper), Circuit 36 (YE/WH) (Lower) Battery Engine to Battery Ground Charging System Warning Indicator Operation Key OFF 12V 0V 12V 12V 0V Off http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 18/110
Key ON - engine off 12V 1-3V (glow plugs off) 12V 12V 0V Illuminated Engine running 13-15V 8-9V 13-15V 13-15V 0V Off NOTE: Make sure to use the latest scan tool software release. 7. If the cause is not visually evident, connect the scan tool to the data link connector (DLC). NOTE: The vehicle communication module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM. 8. If the scan tool does not communicate with the VCM: 1. check the VCM connection to the vehicle. 1. check the scan tool connection to the VCM. 1. refer to MODULE COMMUNICATIONS NETWORK article, No power to the scan tool, to diagnose no communication with the scan tool. 9. If the scan tool does not communicate with the vehicle: 1. verify the ignition key is in the ON position. 1. refer to INTRODUCTION - GASOLINE ENGINES article to diagnose no response from the powertrain control module (PCM). 10. Carry out the network test. 1. If the scan tool responds with no communication for one or more modules, refer to MODULE COMMUNICATIONS NETWORK article. 1. If the network test passes, retrieve and record continuous memory diagnostic trouble codes (DTCs). 11. Clear the continuous DTCs and carry out the self-test diagnostics for the PCM. 12. If the DTCs retrieved are related to the concern, go to Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index or the Instrument Cluster (IC) Diagnostic Trouble Code (DTC) Index. For all other DTCs, refer to MULTIFUNCTION ELECTRONIC MODULES article. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 19/110
13. If no DTCs related to the concern are retrieved, go to Symptom Chart. POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX DTC Description Action P0620 P0623 P1148 P1149 P1397 All Other DTCs Dual generator upper fault detected Dual generator battery lamp circuit fault detected Dual generator lower fault detected Dual generator lower circuit fault detected System voltage out of self-test range - Go to Pinpoint Test T. REFER to INSTRUMENT CLUSTER article. Go to Pinpoint Test U. Go to Pinpoint Test V. Go to Pinpoint Test Q. REFER to the INTRODUCTION - GASOLINE ENGINES article. INSTRUMENT CLUSTER (IC) DIAGNOSTIC TROUBLE CODE (DTC) INDEX DTC Description Action B1317 B1318 All Other DTCs Battery voltage high Battery voltage low - Go to Pinpoint Test Q. Go to Pinpoint Test Q. REFER to MULTIFUNCTION ELECTRONIC MODULES article. Symptom Chart Symptom Chart Condition Possible Sources Action Circuitry The charging system warning indicator is on with the engine running (the charging system voltage does B+ circuit fusible links Upper generator Lower generator Go to Pinpoint Test I. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 20/110
not increase) Powertrain control module (PCM) The charging system warning indicator is off with the ignition switch in the RUN position and the engine off Circuitry Upper generator Lower generator Instrument cluster (IC) Powertrain control module (PCM) Go to Pinpoint Test J. The charging system warning indicator is on with the engine running and the battery increases voltage Circuitry IC Upper generator Lower generator Powertrain control module (PCM) Go to Pinpoint Test K. The charging system warning indicator operates correctly and the battery voltage does not increase B+ circuit fusible links Circuitry Upper generator Lower generator Go to Pinpoint Test L. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 21/110
High key-off loads Circuitry The battery is discharged or battery voltage is low B+ circuit fusible links Upper generator Lower generator Go to Pinpoint Test M. The charging system warning indicator flickers or is intermittent Circuitry Upper generator Lower generator IC Powertrain control module (PCM) Go to Pinpoint Test N. The charging system overcharges (battery voltage is greater than 15.5 volts) A circuit fuse Circuitry Upper generator Lower generator Go to Pinpoint Test O. Battery leakage or damage Battery Circuitry Upper generator Lower generator Go to Pinpoint Test P. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 22/110
The voltage gauge reads high or low Upper generator Lower generator IC Go to Pinpoint Test Q. The generator(s) is noisy Loose bolts/brackets Drive belt Upper generator Lower generator Go to Pinpoint Test R. Radio interference Upper generator Lower generator Wiring/routing In-vehicle entertainment system Go to Pinpoint Test S. Dual generator upper fault detected (P0620) Circuitry B+ circuit fusible links Upper generator Go to Pinpoint Test T. Dual generator lower fault detected (P1148) Circuitry B+ circuit fusible links Lower generator Go to Pinpoint Test U. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 23/110
Dual generator lower circuit fault detected (P1149) Circuitry Lower generator Go to Pinpoint Test V. Dual generator battery lamp circuit fault detected (P0623) Circuitry IC REFER to INSTRUMENT CLUSTER article. Pinpoint Tests Pinpoint Test I: The Charging System Warning Indicator Is On With The Engine Running (The Charging System Voltage Does Not Increase) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is used by the powertrain control module (PCM) to turn off the charging system warning indicator. The positive battery output (B+) circuit 1119 (RD) (upper) / 36 (YE/WH) (lower) is the generator output supplied to the battery and the electrical system. Possible Causes Circuitry B+ circuit fusible links Upper generator Lower generator PCM PINPOINT TEST I: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING (THE CHARGING SYSTEM VOLTAGE DOES NOT INCREASE) I1 CHECK FOR DTCS IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 24/110
With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Do generator DTCs exist? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to I2. I2 CHECK I CIRCUIT 904 (LG/RD) FOR VOLTAGE Key in OFF position. Disconnect the diagnostic tool. Disconnect: Upper Generator C102a Key in ON position. With the key ON, engine OFF, measure the voltage at upper generator C102a-1, circuit 904 (LG/RD), harness side and ground. Is the voltage greater than 10 volts? YES : Go to I4. NO : Go to I3. I3 CHECK I CIRCUIT 1183 (WH/YE) / 904 (LG/RD) FOR AN OPEN Key in OFF position. Disconnect: PCM C1381c Measure the resistance between PCM C1381c-1, circuit 1183 (WH/YE), harness side and upper generator C102a-1, circuit 904 (LG/RD), harness side. Fig 37: Checking I Circuit 1183 (WH/YE) / 904 (LG/RD) For An Open Is the resistance less than 5 ohms? http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 25/110
YES : Go to I8. NO : REPAIR the circuit. TEST the system for normal operation. I4 CHECK THE VOLTAGE TO THE LOWER GENERATOR Key in OFF position. Disconnect: Lower Generator C1251a Key in ON position. NOTE: Make certain the glow plug system is not cycling, or the PCM will not provide voltage on the lower generator I circuit. Measure the voltage between lower generator C1251a-1, circuit 1185 (YE), harness side and ground. Fig 38: Checking The Voltage To The Lower Generator Is the voltage greater than 10 volts? YES : Go to I6. NO : Go to I5. I5 CHECK THE LOWER GENERATOR I CIRCUIT 1185 (YE) FOR AN OPEN Key in OFF position. Connect: Upper Generator C102a Disconnect: Lower Generator C1251a Disconnect: PCM C1381c Measure the resistance between PCM C1381c-4, circuit 1185 (YE), harness http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 26/110
side and lower generator C1251a-1, circuit 1185 (YE), harness side. Fig 39: Checking The Lower Generator I Circuit 1185 (YE) For An Open Is the resistance less than 5 ohms? YES : Go to I8. NO : REPAIR the circuit. TEST the system for normal operation. I6 CHECK THE UPPER GENERATOR OUTPUT Connect: PCM C1381c Key in START position. Carry out the Generator On-Vehicle Load Test and No Load Test on the upper generator. Refer to the Component Tests in this article. Does the upper generator pass the component tests? YES : Go to I7. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. I7 CHECK THE LOWER GENERATOR OUTPUT Key in OFF position. Connect: Lower Generator C1251a Disconnect: Upper Generator C102a Key in START position. NOTE: Note: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 27/110
Carry out the Generator On-Vehicle Load Test and No Load Test on the lower generator. Refer to the Component Tests in this article. Does the lower generator pass the component tests? YES : Go to I8. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. I8 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation. Pinpoint Test J: The Charging System Warning Indicator Is Off With The Ignition Switch In The Run Position And The Engine Off Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation Under normal operation, the charging system warning indicator is on with the key in the ON position and the engine off. With the engine running, the charging system warning indicator is off. Possible Causes Circuitry Powertrain control module (PCM) PINPOINT TEST J: THE CHARGING SYSTEM WARNING INDICATOR IS OFF WITH THE IGNITION SWITCH IN THE RUN POSITION AND THE ENGINE OFF http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 28/110
J1 CHECK FOR DTCS IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Are generator DTCs present? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to J2. J2 CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION Key in OFF position. Disconnect the diagnostic tool. Disconnect: PCM C1381a Key in ON position. With the key ON, engine OFF, connect a fused (15A) jumper wire between PCM C1381a-30, circuit 3090 (VT), harness side and ground. Fig 40: Checking The Charging System Warning Indicator Operation Does the charging system warning indicator illuminate? YES : Go to J3. NO : REFER to INSTRUMENT CLUSTER article to diagnose the charging system warning indicator. J3 CHECK FOR CORRECT PCM OPERATION http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 29/110
Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Pinpoint Test K: The Charging System Warning Indicator Is On With The Engine Running And The Battery Increases Voltage Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit (internal to the generator) is used to feed back a voltage signal from the generator to the voltage regulator. This voltage is monitored by the powertrain control module (PCM) to turn off the charging system warning indicator. The battery positive output (B+) circuit 1119 (RD) (upper), circuit 36 (YE/WH) (lower) is the generator output supplied to the battery and the electrical system. Possible Causes Circuitry Instrument cluster (IC) Lower generator PCM PINPOINT TEST K: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND THE BATTERY INCREASES VOLTAGE K1 CHECK FOR DTCS IN THE PCM Key in OFF position. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 30/110
Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Are generator DTCs present? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to K2. K2 CHECK THE SYSTEM FOR OVERCHARGING Key in OFF position. Disconnect the diagnostic tool. Key in START position. With the engine running and all of the accessories off, measure the voltage at the primary (passenger side) battery terminals while varying the engine rpm. Fig 41: Checking The System For Overcharging Is the voltage greater than 15.5 volts? YES : Go to Pinpoint Test O. NO : Go to K3. K3 CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION Key in OFF position. Disconnect: PCM C1381a Key in ON position. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 31/110
With the key ON, engine OFF, monitor the charging system warning indicator. Is the charging system warning indicator illuminated? YES : Go to K4. NO : Go to K5. K4 CHECK THE CHARGING SYSTEM WARNING INDICATOR CIRCUIT Key in OFF position. Disconnect: IC C220a Measure the resistance between PCM C1381a-30, circuit 3090 (VT) harness side and ground. Fig 42: Checking The Charging System Warning Indicator Circuit Is the resistance greater than 10,000 ohms? YES : REFER to INSTRUMENT CLUSTER article to continue the diagnosis of the IC. NO : REPAIR the circuit. TEST the system for normal operation. K5 CHECK THE LOWER GENERATOR A CIRCUIT Key in OFF position. Disconnect: Lower Generator C1251a Key in ON position. With the key in the ON position, engine OFF, measure the voltage at lower generator C1251a-3, circuit 35 (OG/LB), harness side and ground. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 32/110
Fig 43: Measuring Voltage Between Harness Connector And Ground Is the voltage equal to battery voltage? YES : Go to K6. NO : REPAIR the circuit. TEST the system for normal operation. K6 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation. Pinpoint Test L: The Charging System Warning Indicator Operates Correctly And The Battery Voltage Does Not Increase Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 33/110
During normal operation, the charging system warning indicator is off with the key in the ON position and the engine running. The charging system warning indicator is on with the key in the ON position and the engine off. The generator output is supplied through the battery positive output (B+) circuit 1119 (RD) (upper), circuit 36 (YE/WH) (lower) terminal on the rear of the generator to the battery and electrical system. Possible Causes B+ circuit fusible links Circuitry Upper generator Lower generator Loose or damaged harness connectors PINPOINT TEST L: THE CHARGING SYSTEM WARNING INDICATOR OPERATES CORRECTLY AND THE BATTERY VOLTAGE DOES NOT INCREASE L1 CHECK FOR DTCS IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Do generator DTCs exist? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to L2. L2 CHECK THE UPPER AND LOWER GENERATOR CONNECTIONS Key in OFF position. Disconnect the diagnostic tool. Check the battery terminals and all of the generator connectors for corrosion, damage and correct connections. Are all connections clean and tight? YES : Go to L3. NO : REPAIR the connections as necessary. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 34/110
L3 CHECK THE BATTERY POSITIVE OUTPUT (B+) CIRCUIT 1119 (RD) OF THE UPPER GENERATOR Check the voltage at the upper generator battery positive output B+ terminal, C102c, circuit 1119 (RD), harness side and ground. Fig 44: Checking Upper Generator B+ Voltage Is the voltage equal to battery voltage? YES : Go to L4. NO : REPAIR the circuit. TEST the system for normal operation. L4 CHECK THE BATTERY POSITIVE OUTPUT (B+) CIRCUIT 36 (YE/WH) OF THE LOWER GENERATOR Check the voltage at the lower generator battery positive output (B+) terminal, C102c, circuit 36 (YE/WH), harness side and ground. Fig 45: Measuring Voltage Between B+ Terminal Of Lower Generator And Ground Is the voltage equal to battery voltage? YES : Go to L5. NO : REPAIR the circuit. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 35/110
L5 CHECK THE BATTERY CONDITION Carry out the Battery - Condition Test to determine if the battery can hold a charge and is OK for use. Refer to BATTERY, MOUNTING AND CABLES article. Do the batteries pass the condition test? YES : Go to L6. NO : INSTALL a new battery. TEST the system for normal operation. L6 CHECK THE UPPER GENERATOR OUTPUT Disconnect: Lower Generator C1251a Carry out the Generator On-Vehicle Load Test and No Load Test on the upper generator. Refer to the Component Tests in this article. Does the upper generator pass the component tests? YES : Go to L7. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. L7 CHECK THE LOWER GENERATOR OUTPUT Key in OFF position. Connect: Lower Generator C1251a Disconnect: Upper Generator C102a Key in START position. NOTE: Note: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running, carry out the Generator On-Vehicle Load Test and No Load Test on the lower generator. Refer to the Component Tests in this article. Does the lower generator pass the component tests? YES : The system is OK. VERIFY the symptoms from the Symptom Chart and TEST the system for normal operation. COMPARE to a similar vehicle. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 36/110
Pinpoint Test M: The Battery Is Discharged Or Battery Voltage Is Low Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator output is supplied through the battery positive output (B+) circuit 1119 (RD) (upper), circuit 36 (YE/WH) (lower) terminal on the rear of the generator to the battery and electrical system. During normal operation, the charging system warning indicator is off with the key in the ON position and the engine running. The charging system warning indicator is on with the key in the ON position and the engine off. Possible Causes High key-off loads Battery Upper generator Lower generator PINPOINT TEST M: THE BATTERY IS DISCHARGED OR BATTERY VOLTAGE IS LOW M1 CHECK FOR DTCS IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Are generator DTCs present? YES : Go to the appropriate pinpoint test listed in the Symptom Chart. NO : Go to M2. M2 CHECK THE BATTERY CONDITION Key in OFF position. Disconnect the diagnostic tool. Carry out the Battery - Condition Test to determine if the battery can hold a charge and is OK for use. Refer to BATTERY, MOUNTING AND CABLES article. Does the battery(s) pass the condition test? YES : Go to M3. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 37/110
NO : INSTALL a new battery(s). REFER to BATTERY, MOUNTING AND CABLES article. M3 CHECK THE BATTERY DRAIN Make sure all of the interior lights and switches are off and all of the doors are closed. Carry out the battery drain test. Refer to the Component Tests, Battery - Drain Testing in this article. Is the drain greater than 0.05 amp? YES : REPAIR the battery drain as necessary. NO : Go to M4. M4 CHECK THE UPPER GENERATOR OUTPUT Disconnect: Lower Generator C1251a Key in START position. Carry out the Generator On-Vehicle Load Test and No Load Test on the upper generator. Refer to the Component Tests in this article. Does the upper generator pass the component tests? YES : Go to M5. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. M5 CHECK THE LOWER GENERATOR OUTPUT Key in OFF position. Connect: Lower Generator C1251a Disconnect: Upper Generator C102a Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. Carry out the Generator On-Vehicle Load Test and No Load Test on the lower generator. Refer to the Component Tests in this article. Does the lower generator pass the component tests? YES : Go to M6. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 38/110
NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. M6 CHECK THE OTHER SYSTEMS FOR DRAINS Check for drains from the electronic modules. Refer to the Component Tests, Battery - Electronic Drains Which Shut Off When the Battery Cable is Disconnected in this article. Does the electronic modules pass the component test? YES : CHARGE the batteries. NO : REPAIR as necessary. Pinpoint Test N: The Charging System Warning Indicator Flickers Or Is Intermittent Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation Under normal operation, the charging system warning indicator is on with the key in the ON position and the engine off; and is off with the key in the ON position and the engine running. Possible Causes Circuitry Upper generator Lower generator Powertrain control module (PCM) PINPOINT TEST N: THE CHARGING SYSTEM WARNING INDICATOR FLICKERS OR IS INTERMITTENT N1 CHECK FOR DTCS IN THE PCM Key in OFF position. Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Do generator DTCs exist? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to N2. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 39/110
N2 CHECK THE BATTERY VOLTAGE Key in START position. With the key ON, engine running, and all of the accessories turned off, measure the voltage at the battery(s) while varying the engine rpm. Fig 46: Checking The Battery Voltage Is the voltage greater than 15.5 volts? YES : Go to Pinpoint Test O. NO : Go to N3. N3 CHECK THE CHARGING SYSTEM WARNING INDICATOR OPERATION Key in OFF position. Enter the following diagnostic mode on the diagnostic tool: Active Commands Key in ON position. With the key ON, engine OFF, enter the following diagnostic mode on the diagnostic tool: Active Commands. Command the charging system warning indicator on. Does the charging system warning indicator illuminate? YES : Go to N4. NO : REFER to INSTRUMENT CLUSTER article to diagnose the charging system warning indicator. N4 CHECK THE PCM OPERATION Key in OFF position. Disconnect the diagnostic tool. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 40/110
Key in ON position. With the key ON, engine OFF, monitor the charging system warning indicator. Is the charging system warning indicator illuminated? YES : The PCM is operating correctly. RECHECK the generator circuits (including the generators) for intermittent shorts or opens. TEST the system for normal operation. NO : Go to N5. N5 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. REPEAT the self-test. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. TEST the system for normal operation. Pinpoint Test O: The Charging System Overcharges (Battery Voltage Is Greater Than 15.5 Volts) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes A circuit fuse http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 41/110
Circuitry Upper generator Lower generator PINPOINT TEST O: THE CHARGING SYSTEM OVERCHARGES (BATTERY VOLTAGE IS GREATER THAN 15.5 VOLTS) O1 CHECK FOR DTCS IN THE POWERTRAIN CONTROL MODULE (PCM) Key in OFF position. Connect the diagnostic tool. Key in ON position. With the key ON, engine OFF, check the PCM for DTCs with the diagnostic tool. Are generator DTCs present? YES : Go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Index in this article. NO : Go to O2. O2 CHECK THE BATTERY VOLTAGE Key in OFF position. Disconnect the diagnostic tool. Key in START position. With the key ON, engine running and all of the accessories turned off, measure the voltage at either battery while varying the engine rpm. Fig 47: Checking The Battery Voltage Is the voltage greater than 15.5 volts? http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 42/110
YES : Go to O3. NO : Go to O7. O3 CHECK THE UPPER GENERATOR OUTPUT Key in OFF position. Disconnect: Lower Generator C1251a Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running and all of the accessories turned off, measure the voltage at either battery while varying the engine rpm. Fig 48: Checking The Upper Generator Output Is the voltage greater than 15.5 volts? YES : Go to O4. NO : Go to O5. O4 CHECK THE UPPER GENERATOR A CIRCUIT Key in OFF position. Connect: Lower Generator C1251a Disconnect: Upper Generator C102a Key in ON position. With the key ON, engine OFF, measure the voltage drop between upper generator C102a-3, A circuit 35 (OG/LB) harness side and battery positive http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 43/110
terminal. Fig 49: Checking The Upper Generator A Circuit Is the voltage drop less than 0.5 volt? YES : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. NO : REPAIR the upper generator A circuit 35 (OG/LB) for high resistance. CLEAR the DTCs. REPEAT the self-test. O5 CHECK THE LOWER GENERATOR OUTPUT Key in OFF position. Disconnect: Upper Generator C102a Connect: Lower Generator C1251a Key in START position. NOTE: After starting the engine, wait at least 2 minutes for glow plugs to stop cycling. With the engine running and all of the accessories turned off, measure the voltage at either battery while varying the engine rpm. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 44/110
Fig 50: Checking The Lower Generator Output Is the voltage greater than 15.5 volts? YES : Go to O6. NO : Go to O7. O6 CHECK THE LOWER GENERATOR A CIRCUIT Key in OFF position. Connect: Upper Generator C102a Disconnect: Lower Generator C1251a Key in ON position. With the key ON, engine OFF, measure the voltage drop between lower generator C1251a-3, A circuit 35 (OG/LB) harness side and positive battery terminal. Fig 51: Check The Lower Generator A Circuit Is the voltage drop less than 0.5 volt? YES : INSTALL a new lower generator. REFER to GENERATOR AND http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 45/110
REGULATOR article. CLEAR the DTCs. REPEAT the self-test. NO : REPAIR A circuit 35 (OG/LB) for high resistance. CLEAR the DTCs. REPEAT the self-test. O7 CHECK THE GROUNDS Key in OFF position. Check the ground connections between the generators and the engine, and the batteries and the engine. Are all the ground connections clean and tight? YES : CHECK both the upper and lower generator A circuits for intermittent opens/shorts. REPAIR as necessary. CLEAR the DTCs. REPEAT the selftest. NO : REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. Pinpoint Test P: Battery Leakage Or Damage Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The battery(s) should be free of any damage and should not exhibit any signs of leakage. Possible Causes Battery Upper generator Lower generator PINPOINT TEST P: BATTERY LEAKAGE OR DAMAGE P1 CHECK FOR ACID LEAKAGE AND DAMAGE Check for acid damage to both the battery wire harness and to the body. Is acid damage present? YES : REPAIR the damaged areas as necessary. NO : Go to P2. P2 CHECK THE CHARGING SYSTEM FOR OVERCHARGING Key in START position. NOTE: After starting the engine, http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 46/110
wait at least 2 minutes for the glow plugs to stop cycling. With the engine running and all of the accessories off, increase the engine speed to 2,000 rpm and measure the voltage at the battery(s). Fig 52: Checking The Charging System For Overcharging Is the voltage greater than 15.5 volts? YES : Go to Pinpoint Test O. NO : Go to P3. P3 CHECK THE BATTERY MOUNTING Key in OFF position. Check both batteries for correct mounting in the battery trays. Are the batteries correctly mounted? YES : Go to P4. NO : REPAIR as necessary. TEST the system for normal operation. P4 CHECK FOR BATTERY CONTACT Check both batteries to make sure there are no fasteners or other parts contacting the battery case causing excess pressure. Is anything contacting the battery case? YES : REPAIR as necessary. TEST the system for normal operation. NO : Go to P5. P5 CHECK THE BATTERY CASE FOR DAMAGE Check both battery cases for damage, such as cracks or poor seals. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 47/110
Are the batteries OK? YES : Go to P6. NO : INSTALL a new battery(s). REFER to BATTERY, MOUNTING AND CABLES article. TEST the system for normal operation. P6 CHECK THE BATTERY CAPACITY Check the battery capacity of both batteries. Refer to the Battery - Condition Test in BATTERY, MOUNTING AND CABLES article. Do the batteries pass the condition test? YES : The system is OK. TEST the system for normal operation. NO : INSTALL a new battery(s). REFER to BATTERY, MOUNTING AND CABLES article. TEST the system for normal operation. Pinpoint Test Q: The Voltage Gauge Reads High Or Low Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The voltage gauge needle reads approximately in the middle of the gauge during engine operation. The voltage gauge needle drops when the glow plugs cycle on and returns to the middle position when the glow plugs cycle off. Possible Causes Upper generator Lower generator PINPOINT TEST Q: THE VOLTAGE GAUGE READS HIGH OR LOW Q1 CHECK THE BATTERY VOLTAGE Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running and all of the accessories turned off, increase the engine speed to 2,000 rpm and measure the voltage at the battery(s). http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 48/110
Fig 53: Checking The Battery Voltage Is the battery voltage more than 15.5 volts or less than 13 volts? YES : For voltage greater than 15.5 volts, go to Pinpoint Test O. For voltage lower than 13 volts, go to Pinpoint Test M. NO : Go to Q2. Q2 CHECK THE VOLTAGE GAUGE OPERATION NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running, monitor the voltage gauge reading and the battery(s) voltage. Fig 54: Checking The Voltage Gauge Operation Are the voltage readings consistent? YES : The voltage gauge is operating normally. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 49/110
NO : The voltage gauge is inaccurate. REFER to INSTRUMENT CLUSTER article to continue diagnosis of the instrument cluster (IC). Pinpoint Test R: The Generator(S) Is Noisy Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator is belt-driven by the engine accessory drive system. Possible Causes Loose bolts/brackets Drive belt Upper generator Lower generator PINPOINT TEST R: THE GENERATOR(S) IS NOISY R1 CHECK THE DRIVE BELT AND MOUNTING BRACKETS Key in OFF position. Check the drive belt for damage and to verify correct installation. Refer to ACCESSORY DRIVE article. Check the generator mounting brackets for loose bolts or misalignment. Are the accessory drive and generator mounting brackets OK? YES : Go to R2. NO : REPAIR as necessary. TEST the system for normal operation. R2 CHECK THE GENERATOR PULLEY(S) Check for a bent, loose, or misaligned generator pulley(s). Are the generator pulley(s) OK? YES : Go to R3. NO : INSTALL a new pulley(s) as necessary. TEST the system for normal operation. R3 CHECK THE LOWER GENERATOR FOR ELECTRICAL NOISE Disconnect: Lower Generator C1251a Key in START position. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 50/110
With the engine running, use a stethoscope or equivalent listening device to probe the lower generator for noise. Is the lower generator noisy? YES : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : Go to R4. R4 CHECK THE UPPER GENERATOR FOR ELECTRICAL NOISE Key in OFF position. Disconnect: Upper Generator C102a Key in START position. With the engine running, use a stethoscope or equivalent listening device to probe the upper generator for noise. Is the upper generator noisy? YES : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : REFER to ENGINE SYSTEM - GENERAL INFORMATION article to diagnose the source of the engine noise. Pinpoint Test S: Radio Interference Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator radio suppression equipment reduces interference transmitted by the vehicle electrical system through the speakers. Possible Causes Upper generator Lower generator Wiring/routing In-vehicle entertainment system PINPOINT TEST S: RADIO INTERFERENCE S1 VERIFY THE RADIO INTERFERENCE FROM THE UPPER GENERATOR http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 51/110
NOTE: If the original equipment manufactured (OEM) radio unit has been replaced, the vehicle may not pass this test. Return the vehicle to OEM condition before following this pinpoint test. Key in START position. Start and run the engine. Tune the radio to a station where the interference is present. Key in OFF position. Disconnect: Upper Generator C102a Key in START position. Start and run the engine. Is interference present with the upper generator disconnected? YES : Go to S2. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. S2 VERIFY THERE IS RADIO INTERFERENCE FROM THE LOWER GENERATOR Key in OFF position. Connect: Upper Generator C102a Disconnect: Lower Generator C1251a Key in START position. Verify the interference is present with the lower generator disconnected. Is the interference still present? YES : REFER to INFORMATION AND ENTERTAINMENT SYSTEMS article for diagnosis and testing of the in-vehicle entertainment system. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Pinpoint Test T: Dual Generator Upper Fault Detected (P0620) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 52/110
Normal Operation The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes Circuitry B+ circuit fusible links Upper generator PINPOINT TEST T: DUAL GENERATOR UPPER FAULT DETECTED (P0620) T1 CHECK THE UPPER GENERATOR CONNECTIONS Key in OFF position. Disconnect: Upper Generator C102c and C102a Check the upper generator connectors for damage and correct connection. Connect: Upper Generator C102c and C102a Are the upper generator connectors OK and correctly connected? YES : Go to T2. NO : REPAIR the connections as necessary. CLEAR the DTCs. REPEAT the self-test. T2 CHECK THE UPPER GENERATOR B+ VOLTAGE Measure the voltage between B+ terminal of the upper generator C102c, circuit 1119 (RD) harness side and ground. Fig 55: Checking Upper Generator B+ Voltage Is the voltage equal to battery voltage? http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 53/110
YES : Go to T3. NO : CHECK the B+ circuit 1119 (RD) including the fusible links. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. T3 CHECK THE UPPER GENERATOR A CIRCUIT FOR VOLTAGE Disconnect: Upper Generator C102a Measure the voltage between upper generator C102a-3, A circuit 35 (OG/LB), harness side and ground. Fig 56: Checking The Upper Generator A Circuit For Voltage Is the voltage equal to battery voltage? YES : Go to T4. NO : CHECK the upper generator A circuit 35 (OG/LB) including the fusible links. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. T4 CHECK THE UPPER GENERATOR I CIRCUIT FOR VOLTAGE Key in ON position. With the key ON, engine OFF, measure the voltage between upper generator C102a-1, I circuit 904 (LG/RD), harness side and ground. Is the voltage greater than 10 volts? YES : Go to T6. NO : Go to T5. T5 CHECK THE UPPER GENERATOR I CIRCUIT FOR AN OPEN OR SHORT TO GROUND Key in OFF position. Disconnect: PCM C1381c http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 54/110
Measure the resistance between generator C102a-1, I circuit 904 (LG/RD) harness side and PCM C1381c-1, circuit 1183 (WH/YE) harness side; and between generator C102a-1, I circuit 904 (LG/RD) harness side and ground. Fig 57: Checking The Upper Generator I Circuit For An Open Or Short To Ground Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? YES : Go to T8. NO : REPAIR I circuit 1183 (WH/YE)/904 (LG/RD). CLEAR the DTCs. REPEAT the self-test. T6 CHECK THE UPPER GENERATOR VOLTAGE Disconnect: Lower Generator C1251a Connect: Upper Generator C102a Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running, measure the voltage at the battery(s). http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 55/110
Fig 58: Checking The Upper Generator Voltage Is the voltage greater than 13 volts? YES : Go to T7. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. T7 CHECK THE UPPER GENERATOR OUTPUT Carry out the Generator On-Vehicle Load Test and No Load Test on the upper generator. Refer to the Component Tests in this article. Does the upper generator pass the component tests? YES : The system is operating normally. CONNECT all of the connectors. CLEAR the DTCs. REPEAT the self-test. NO : INSTALL a new upper generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. T8 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 56/110
NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. Pinpoint Test U: Dual Generator Lower Fault Detected (P1148) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes Circuitry B+ circuit fusible links Lower generator PINPOINT TEST U: DUAL GENERATOR LOWER FAULT DETECTED (P1148) U1 CHECK THE LOWER GENERATOR CONNECTIONS Key in OFF position. Disconnect: Lower Generator C1251c, C1251a Check the lower generator connectors for damage and correct connection. Connect: Lower Generator C1251c, C1251a Are the lower generator connectors OK and correctly connected? YES : Go to U2. NO : REPAIR the connectors as necessary. CLEAR the DTCs. REPEAT the self-test. U2 CHECK THE LOWER GENERATOR B+ VOLTAGE Measure the voltage between B+ terminal C1251c of the lower generator and ground. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 57/110
Fig 59: Measuring Voltage Between B+ Terminal Of Lower Generator And Ground Is the voltage equal to battery voltage? YES : Go to U3. NO : CHECK the B+ circuit 36 (YE/WH) including the fusible links. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. U3 CHECK THE LOWER GENERATOR A CIRCUIT Disconnect: Lower Generator C1251a Measure the voltage between lower generator C1251a-3, A circuit 35 (OG/LB), harness side and ground. Fig 60: Checking The Lower Generator A Circuit Is the voltage greater than 10 volts? YES : Go to U4. NO : CHECK the lower generator A circuit 35 (OG/LB) including the fusible links. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. U4 CHECK THE LOWER GENERATOR I CIRCUIT FOR VOLTAGE http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 58/110
Key in ON position. NOTE: Wait at least 2 minutes for the glow plugs to stop cycling. With the key ON, engine OFF, measure the voltage between lower generator C1251a-1, circuit 1185 (YE), harness side and ground. Fig 61: Checking The Lower Generator I Circuit For Voltage Is the voltage greater than 10 volts? YES : Go to U6. NO : Go to U5. U5 CHECK THE LOWER GENERATOR I CIRCUIT FOR AN OPEN OR A SHORT TO GROUND Key in OFF position. Disconnect: PCM C1381c Key in ON position. Measure the resistance between lower generator C1251a-1, I circuit 1185 (YE), harness side and PCM C1381c-4, circuit 1185 (YE), harness side; and between lower generator C1251a-1, I circuit 1185 (YE) harness side and ground. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 59/110
Fig 62: Checking The Lower Generator I Circuit For An Open Or A Short To Ground Is the resistance less than 5 ohms between the generator and the PCM, and greater than 10,000 ohms between the generator and ground? YES : Go to U8. NO : REPAIR the I circuit 1185 (YE). CLEAR the DTCs. REPEAT the selftest. U6 CHECK THE LOWER GENERATOR VOLTAGE Disconnect: Upper Generator C102a Connect: Lower Generator C1251a Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running, measure the voltage at the battery(s). http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 60/110
Fig 63: Checking The Lower Generator Voltage Is the voltage greater than 13 volts? YES : Go to U7. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. U7 CHECK THE LOWER GENERATOR OUTPUT Carry out the Generator On-Vehicle Load Test and No Load Test on the lower generator. Refer to the Component Tests in this article. Does the lower generator pass the component tests? YES : The system is operating normally. CONNECT all of the connectors. CLEAR the DTCs. REPEAT the self-test. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. U8 CHECK FOR CORRECT PCM OPERATION Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 61/110
NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. Pinpoint Test V: Dual Generator Lower Circuit Fault Detected (P1149) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes Circuitry Lower generator PINPOINT TEST V: DUAL GENERATOR LOWER CIRCUIT FAULT DETECTED (P1149) V1 CHECK THE LOWER GENERATOR I CIRCUIT FOR A SHORT TO VOLTAGE Key in OFF position. Disconnect: PCM C1381c Disconnect: Lower Generator C1251a Key in ON position. With the key ON, engine OFF, measure the voltage between PCM C1381c- 4, circuit 1185 (YE), harness side and ground. Fig 64: Checking The Lower Generator I Circuit For A Short To Voltage Is the voltage greater than 0 volts? http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 62/110
YES : REPAIR the I circuit 1185 (YE). CLEAR the DTCs. REPEAT the selftest. NO : Go to V2. V2 CHECK THE LOWER GENERATOR I CIRCUIT Key in OFF position. Connect: PCM C1381c Key in START position. NOTE: After starting the engine, wait at least 2 minutes for the glow plugs to stop cycling. With the engine running, measure the voltage between lower generator C1251a-1, I circuit 1185 (YE), harness side and ground. Fig 65: Checking The Lower Generator I Circuit Is the voltage greater than 0 volts? YES : Go to V4. NO : Go to V3. V3 CHECK THE PCM OPERATION Key in OFF position. Connect: PCM C1381c Key in ON position. With the key ON, engine OFF, carry out a glow plug test with the diagnostic tool (refer to the INTRODUCTION - GASOLINE ENGINES article for test procedures). Measure the voltage at lower generator C1251a-1, I circuit http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 63/110
1185 (YE) harness side and ground while carrying out the glow plug test. Fig 66: Checking The PCM Operation Is the voltage greater than 0 volts with the glow plugs on? YES : Go to V4. NO : INSTALL a new lower generator. REFER to GENERATOR AND REGULATOR article. CLEAR the DTCs. REPEAT the self-test. V4 CHECK FOR CORRECT PCM OPERATION Component Tests Battery - Drain Testing Disconnect all of the PCM connectors. Check for: corrosion. pushed-out pins. Connect all of the PCM connectors and make sure they seat correctly. Operate the system and verify the concern is still present. Is the concern still present? YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - DIESEL ENGINE article. TEST the system for normal operation. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. WARNING: Do not attempt this test on a lead-acid battery that has recently been http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 64/110
recharged. Explosive gases can cause personal injury. Failure to follow these instructions may result in personal injury. CAUTION: To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A. NOTE: No factory-equipped vehicle should have more than a 50 milliamp (ma) (0.050 amp) draw. NOTE: Many electronic modules draw 10 ma or more continuously. NOTE: Use an in-line ammeter between the positive battery or negative post and its respective cable. NOTE: Typically, a drain of approximately 1 amp can be attributed to an engine compartment lamp, glove compartment lamp, or interior lamp staying on continuously. Other component failures or wiring shorts may be located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading falls to an acceptable level. If the drain is still not located after checking all the fuses, it may be due to the generator. NOTE: To accurately test the drain on a battery, an in-line digital ammeter must be used. Using a test lamp or voltmeter is not an accurate method due to the number of electronic modules. Check for current drains on the battery in excess of 50 ma (0.050 amp) with all of the electrical http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 65/110
accessories off and the vehicle at rest. Current drains can be tested with the following procedure. 1. Make sure engine compartment and interior fuse panels are accessible without turning on the interior and underhood lights. 2. Drive the vehicle at least 5 minutes and over 30 mph to turn on and activate the vehicle systems. 3. Allow the vehicle to sit with the key off for at least 45 minutes to allow the modules to time out/power down. 4. Connect a fused (15A) jumper wire between the negative battery cable and negative battery post to prevent modules from resetting and to catch capacitive drains. 5. Disconnect the negative battery cable from the post without breaking the connection of the jumper wire. NOTE: It is very important continuity is not broken between the battery and the negative cable when connecting the meter. If this happens, the entire procedure must be repeated. 6. Connect the tester between the negative battery cable and post. The meter must be capable of reading milliamps and should have a 10 amp capability. NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity. 7. Remove the jumper wire. NOTE: Amperage draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference. 8. No production vehicle should have more than a 50 ma draw. 9. If the draw is found to be excessive, pull the fuses from the central junction box (CJB) one at a time and note the current drop. Do not reinstall the fuses until you are finished testing. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 66/110
10. If the draw is still excessive, remove fuses from the battery junction box (BJB) one at a time and note the current drop. Do not reinstall the fuses until you are finished testing. 11. Check the wiring schematic in the wiring diagram for any circuits that run from the battery without passing through the BJB. Disconnect these circuits if the draw is still excessive. Generator On-Vehicle Tests CAUTION: To prevent damage to the generator, do not make jumper wire connections except as directed. CAUTION: Do not allow any metal object to come in contact with the housing and the internal diode cooling fins with the key on or off. A short circuit will result and burn out the diodes. NOTE: The battery posts and cable clamps must be clean and tight for accurate meter indications. NOTE: Refer to the battery tester manual for complete directions on checking out the charging system. 1. Turn off all lamps and electrical components. 2. Place the vehicle in NEUTRAL and apply the parking brake. 3. Carry out the Load Test and No-Load Test according to the following component tests: Generator On-Vehicle Test - Load Test 1. Switch the tester to the ammeter function. 2. Connect the positive and negative leads of the tester to the corresponding battery terminals. 3. Connect the current probe to the generator B+ output terminal, circuit 1119 (RD) (upper) / circuit 36 (YE/WH) (lower). http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 67/110
NOTE: Make sure to disconnect the generator that is not being tested. 4. With the engine running at 2,000 rpm, adjust the tester load bank to determine the output of the generator. The generator output should be at or greater than the applicable graphs below. If not, refer back to the pinpoint test or Go to Symptom Chart for the diagnostic procedures. Fig 67: 4G (Lower), 75/120 amps Fig 68: VR42 (Upper), 95/140 amps 5. With the engine running, turn the A/C on, (if equipped) the blower motor on HIGH and the headlamps on high beam. 6. Increase the engine speed to approximately 2,000 rpm. The voltage should increase a minimum of 0.5 volt above the base voltage. 1. Backprobe the I circuit at the generator connector (connector plugged in) and measure the I circuit voltage. If the voltage is less than 2 volts, install a new generator. Refer to GENERATOR AND REGULATOR article. 1. If the voltage does not increase as specified, refer back to the pinpoint test or Go to Symptom Chart for the diagnostic procedures. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 68/110
1. If the voltage increases as specified, the charging system is operating normally. Carry out the Generator On-Vehicle Tests - No-Load Test below. Generator On-Vehicle Test - No-Load Test 1. Switch the tester to the voltmeter function. 2. Connect the positive voltmeter lead to the generator B+ output terminal, circuit 1119 (RD) (upper) / circuit 36 (YE/WH) (lower) and the negative voltmeter lead to ground. 3. Turn all of the electrical accessories off. 4. With the engine running at 2,000 rpm, check the generator output voltage. The voltage should be between 13.0 and 15.5 volts. If not, refer back to the pinpoint test or Go to Symptom Chart for the diagnostic procedures. Charging System - Single Generator Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105- R0057 or equivalent SABRE Premium Battery and Electrical System Tester 010-00736 or equivalent Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool Flex Probe Kit 105- R025B http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 69/110
Micro 490 Digital Battery Analyzer 162-00004 or equivalent Principles Of Operation In the single generator system, with the key in the ON position, voltage is applied through the charging system warning indicator I circuit to the voltage regulator. This turns the regulator on, allowing current to flow from the battery sense A circuit to the generator field coil. When the engine is started, the generator begins to generate alternating current (AC) which is internally converted to direct current (DC). This current is then supplied to the electrical system through the output terminal (B+) of the generator. Once the generator begins generating current, a voltage signal is taken from the generator stator and fed back to the regulator through the stator circuit 4 (WH/BK). This voltage feedback signal (typically one-half of the battery voltage) is used to turn off the charging system warning indicator on the single generator system. Gas engines have an external stator circuit and diesel engines have an internal stator circuit. With the system functioning normally, the generator output current is determined by the voltage of the A circuit. This A circuit voltage (battery sense circuit) is compared to a set voltage internal to the regulator, and the regulator controls the generator field current to maintain correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures than in warm temperatures. This allows for better battery recharge in the winter and reduces the chance of overcharging in the summer. The single generator system consists of the generator mounted on the top right of the engine (diesel) or top center of the engine (gas). The gas engines use a 3G 115-amp generator with a 2.71:1 pulley ratio. The 6.0L diesel engine uses a 6G 110-amp (standard) generator with a 2:79 pulley ratio and a snowplow option is available for only the 6.0L diesel that includes a VR42 140- amp generator with a 2.79:1 pulley ratio. Circuit Description Positive Battery Output (B+) Circuit 36 (YE/WH) (Gas Engines) / Circuit 1119 (RD) (Diesel Engines) The generator output is supplied through the positive battery output (B+) terminal on the rear of the generator to the battery and the electrical system. I Circuit 904 (LG/RD) Single Generator The I (ignition) circuit is used to turn on the voltage regulator. This circuit is powered up when the key is in the ON position. Voltage is supplied from the ignition switch to the central junction box (CJB) fuse 45 (10A), then to the instrument cluster (IC) and through the charging system warning indicator (battery icon) to the generator. This circuit is also used to turn the charging system warning indicator on if there is a fault in the charging system operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 70/110
S Circuit 4 (WH/BK) (Gas Engines) The S (stator) circuit 4 (WH/BK) is used to feed back a voltage signal externally from the generator stator to the regulator. This voltage feedback signal (typically half the battery voltage) is used by the regulator to turn off the charging system warning indicator. Gas engines have an external stator circuit and diesel engines have an internal stator circuit. A Circuit 35 (OG/LB) The A circuit or battery sense circuit is used to sense battery voltage. This voltage is used by the regulator to determine generator output. This circuit is also used to supply current to the generator field, which determines generator output. Inspection And Verification WARNING: Batteries contain sulfuric acid. Avoid contact with skin, eyes or clothing. Also, shield your eyes when working near batteries to protect against possible splashing of the acid solution. In case of acid contact with skin or eyes, flush immediately with water for a minimum of 15 minutes and get prompt medical attention. If acid is swallowed, call a physician immediately. Failure to follow these instructions may result in personal injury. WARNING: Batteries normally produce explosive gases. Therefore, do not allow flames, sparks or lighted substances to come near the battery. When charging or working near a battery, always shield your face and protect your eyes. Always provide ventilation. Failure to follow these instructions may result in personal injury. WARNING: When lifting a battery, excessive pressure on the end walls could cause acid to spew through the vent caps, resulting in personal injury, damage to the vehicle or battery. Lift with a battery carrier or with your hands on opposite corners. Failure to follow these instructions may result in personal injury. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 71/110
CAUTION: Do not make jumper connections except as directed. Incorrect connections may damage the voltage regulator test terminals, fuses, or fusible links. CAUTION: Do not allow any metal object to come in contact with the generator housing and internal diode cooling fins. A short circuit may result and burn out the diodes. NOTE: All voltage measurements are referenced to the negative (-) battery post unless otherwise specified. 1. Verify the customer concern. 2. Visually inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical 1. Battery 2. Generator drive belt 3. Generator pulley 1. Charging system warning indicator 2. Battery charge 3. Circuitry 4. Cables 3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step. NOTE: Make sure to use the latest scan tool software release. 4. If the cause is not visually evident, connect the scan tool to the data link connector (DLC). 5. Check the operation of the charging system warning indicator in the instrument cluster (IC) as follows: 1. With the key in the OFF position, the charging system warning indicator http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 72/110
should be off. 1. With the key in the ON position and the engine off, the charing system warning indicator should be off. 1. With the engine running, the charging system warning indicator should be off. 6. Turn off the headlamps and the A/C system (if equipped). Turn the climate control blower to low/off. Check the battery voltage before and after starting the engine to determine if the battery voltage increases. NOTE: The vehicle communication module (VCM) LED prove out confirms power and ground from the DLC are provided to the VCM. 7. If the scan tool does not communicate with the VCM: 1. check the VCM connection to the vehicle. 1. check the scan tool connection to the VCM. 1. refer to MODULE COMMUNICATIONS NETWORK article, No power to the scan tool, to diagnose no communication with the scan tool. 8. If the scan tool does not communicate with the vehicle: 1. verify the ignition key is in the ON position. 1. refer to MODULE COMMUNICATIONS NETWORK article to diagnose no response from the powertrain control module (PCM). 9. Carry out the network test. 1. If the scan tool responds with no communication for one or more modules, refer to MODULE COMMUNICATIONS NETWORK article. 1. If the network test passes, retrieve and record continuous memory diagnostic trouble codes (DTCs). 10. Clear the continuous DTCs and carry out the self-test diagnostics for the Powertrain Control Module (PCM) and the IC. 11. If the DTCs retrieved are related to the concern, go to the Instrument Cluster (IC) Diagnostic Trouble Code (DTC) Index. For all other DTCs, refer to MULTIFUNCTION ELECTRONIC MODULES article. 12. If no DTCs related to the concern are retrieved, go to Symptom Chart. INSTRUMENT CLUSTER (IC) DIAGNOSTIC TROUBLE CODE (DTC) INDEX http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 73/110
DTC Description Source Action B1317 Battery Voltage High IC Go to Pinpoint Test C. B1318 Battery Voltage Low IC Go to Pinpoint Test A. Symptom Chart Symptom Chart Condition Possible Sources Action High key-off current drain(s) The battery is discharged or battery voltage is low Engine, generator and battery grounds Positive battery cable Circuitry Battery Generator Go to Pinpoint Test A. The charging system warning indicator is on with the engine running (the charging system voltage does not increase) Circuitry Voltage regulator Generator Go to Pinpoint Test B. The charging system overcharges (battery voltage is greater than 15.5 volts) Circuitry Voltage regulator Generator Go to Pinpoint Test C. The charging system warning indicator is on with the engine running Circuitry Instrument cluster (IC) Go to Pinpoint http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 74/110
and the battery increases voltage Voltage regulator Generator Test D. The charging system warning indicator is off with the ignition switch in the RUN position and the engine off Bulb Circuitry IC Voltage regulator Generator Go to Pinpoint Test E. The charging system warning indicator flickers or is intermittent Corroded terminal(s) Fusible link(s) Circuitry Voltage regulator Generator Go to Pinpoint Test F. The generator is noisy Accessory drive belt Loose bolts/brackets Generator/pulley Go to Pinpoint Test G. Radio interference Generator Circuitry In-vehicle entertainment system Go to Pinpoint Test H. Pinpoint Tests Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 75/110
connector information. Pinpoint Test A: The Battery Is Discharged Or Battery Voltage Is Low Normal Operation The generator output is supplied through the positive battery output (B+) circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) terminal on the rear of the generator to the battery and electrical system. During normal operation, the charging system warning indicator is off with the key in the ON position and the engine running. The charging system warning indicator is on with the key in the ON position and the engine off. Possible Causes High key-off current drain(s) Engine, generator and battery grounds Positive battery cable Generator B+ circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) high resistance Battery Generator PINPOINT TEST A: THE BATTERY IS DISCHARGED OR BATTERY VOLTAGE IS LOW A1 CHECK THE BATTERY CONDITION Carry out the Battery - Condition Test to determine if the battery can hold a charge and is OK for use. Refer to BATTERY, MOUNTING AND CABLES article. Does the battery pass the condition test? YES : Go to A2. NO : INSTALL a new battery. REFER to BATTERY, MOUNTING AND CABLES article. TEST the system for normal operation. A2 CHECK THE GENERATOR OUTPUT Carry out the Generator On-Vehicle Load Test and No Load Test. Refer to the Component Tests in this article. Does the generator pass the component tests? YES : Go to A3. NO : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 76/110
A3 CHECK FOR CURRENT DRAINS Carry out the Battery - Drain Testing. Refer to the Component Tests in this article. Are any circuits causing excessive current drains? YES : REPAIR as necessary. TEST the system for normal operation. NO : Go to A4. A4 CHECK THE VEHICLE GROUNDS Key in START position. With the engine running, measure the voltage drop between the generator housing and the negative battery terminal. Fig 69: Check The Vehicle Grounds Is the voltage drop less than 0.1 volt? YES : Go to A5. NO : CHECK the engine ground, generator ground and the battery ground for corrosion. TEST the system for normal operation. A5 CHECK THE VOLTAGE DROP IN THE B+ CIRCUIT 36 (YE/WH) (GAS ENGINES) / CIRCUIT 1119 (RD) (DIESEL ENGINES) With the engine running, measure the voltage drop between the generator B+ C102c, circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) and the positive battery terminal. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 77/110
Fig 70: Check The Voltage Drop In The B+ Circuit 36 (YE/WH) (Gas Engines) / Circuit 1119 (RD) (Diesel Engines) Is the voltage drop less than 0.1 volt? YES : CHECK if the customer left any electrical system(s) on or if there is an intermittent excessive battery draw. TEST the system for normal operation. NO : CHECK for any corrosion in the B+ circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines), positive battery cable and/or connections. REPAIR as necessary. TEST the system for normal operation. Pinpoint Test B: The Charging System Warning Indicator Is On With The Engine Running (The Charging System Voltage Does Not Increase) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit 4 (WH/BK) (external on gas engines and internal on diesel engines) is used to feed back a voltage signal from the generator stator to the regulator. This voltage feedback signal (typically half the battery voltage) is used by the regulator to turn off the charging system warning indicator. The positive battery output (B+) circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) is the generator output supplied to the battery and the electrical system. Possible Causes Circuitry Voltage regulator Generator PINPOINT TEST B: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING (THE CHARGING SYSTEM VOLTAGE DOES NOT INCREASE) B1 CHECK THE GENERATOR B+ CIRCUIT 36 (YE/WH) (GAS ENGINES) / CIRCUIT http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 78/110
1119 (RD) (DIESEL ENGINES) Key in OFF position. Measure the voltage between generator B+ C102c, circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines), component side and ground. Fig 71: Check The Generator B+ Circuit 36 (YE/WH) (Gas Engines) / Circuit 1119 (RD) (Diesel Engines) Is the voltage equal to positive battery voltage (B+)? YES : Go to B2. NO : REPAIR the circuit. TEST the system for normal operation. B2 CHECK THE GENERATOR A CIRCUIT 35 (OG/LB) Disconnect: Generator C102a Measure the voltage between generator C102a-3, circuit 35 (OG/LB), harness side and ground. Fig 72: Checking The Generator A Circuit 35 (OG/LB) Is the voltage equal to positive battery voltage (B+)? YES : Go to B3. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 79/110
NO : REPAIR the circuit. TEST the system for normal operation. B3 CHECK THE I CIRCUIT 904 (LG/RD) FOR AN OPEN Key in ON position. With the key in the ON position and engine off, measure the voltage between generator C102a-1, circuit 904 (LG/RD), harness side and ground. Fig 73: Check The I Circuit 904 (LG/RD) For An Open Is the voltage equal to positive battery voltage (B+)? YES : Go to B4. NO : REPAIR the circuit. TEST the system for normal operation. B4 CHECK FOR VOLTAGE DROP IN THE B+ CIRCUIT 36 (YE/WH) (GAS ENGINES) / CIRCUIT 1119 (RD) (DIESEL ENGINES) Key in OFF position. Connect: Generator C102a Key in START position. With the engine running, turn the headlamps on and the blower motor to the high position. With the engine at approximately 2,000 rpm, measure the voltage drop between generator C102c, circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines), component side and the positive battery terminal. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 80/110
Fig 74: Check For Voltage Drop In The B+ Circuit 36 (YE/WH) (Gas Engines) / Circuit 1119 (RD) (Diesel Engines) Is the voltage drop less than 0.5 volt? YES : Go to B5. NO : REPAIR the high resistance in the B+ circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines). TEST the system for normal operation. B5 CHECK THE GENERATOR INTEGRITY With the engine running at approximately 2,000 rpm, full-field the generator by grounding the F (field) terminal on the voltage regulator. Does the charging system achieve approximately 75% of full output? YES : INSTALL a new regulator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. Pinpoint Test C: The Charging System Overcharges (Battery Voltage Is Greater Than 15.5 Volts) Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator output is determined by the voltage of the A circuit 35 (OG/LB). The A circuit voltage is compared to a set voltage internal to the regulator and the regulator controls the generator field current to maintain the correct generator output. The set voltage varies with temperature and is typically higher in cold temperatures and lower in warm temperatures. Possible Causes Circuitry http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 81/110
Voltage regulator Generator PINPOINT TEST C: THE CHARGING SYSTEM OVERCHARGES (BATTERY VOLTAGE IS GREATER THAN 15.5 VOLTS) C1 CHECK FOR VOLTAGE DROP IN A CIRCUIT 35 (OG/LB) Key in OFF position. Disconnect: Generator C102a Key in ON position. Measure the voltage drop between generator C102a-3, circuit 35 (OG/LB), harness side and positive battery terminal. Fig 75: Checking For Voltage Drop In A Circuit 35 (OG/LB) Is the voltage drop less than 0.5 volt? YES : Go to C2. NO : REPAIR the high resistance in the A circuit 35 (OG/LB). TEST the system for normal operation. C2 CHECK THE GENERATOR AND BATTERY GROUND CONNECTIONS Key in OFF position. Check the ground connections between the generator and the engine, and between the battery and the engine. Are all ground connections clean and tight? YES : INSTALL a new regulator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : REPAIR the ground connections as necessary. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 82/110
Pinpoint Test D: The Charging System Warning Indicator Is On With The Engine Running And The Battery Increases Voltage Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation With the engine running, the charging system warning indicator is off. The sense A circuit 35 (OG/LB) to the generator field coil is 13-15 volts. The S (stator) circuit 4 (WH/BK) is used to feed back a voltage signal externally (gas engines) from the generator to the voltage regulator. This circuit is internal to the generator on diesel engines. This voltage feedback signal (typically half the battery voltage) is used by the regulator to turn off the charging system warning indicator. The positive battery output (B+) circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) is the generator output supplied to the battery and the electrical system. Possible Causes Circuitry Instrument cluster (IC) Voltage regulator Generator PINPOINT TEST D: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND THE BATTERY INCREASES VOLTAGE D1 CHECK THE I CIRCUIT 904 (LG/RD) FOR A SHORT TO GROUND Key in OFF position. Disconnect: Generator C102a Key in ON position. With the key in the ON position, check the charging system warning indicator. Is the charging system warning indicator illuminated? YES : REPAIR the I circuit 904 (LG/RD). TEST the system for normal operation. NO : If gas engine, go to D2. If diesel engine, INSTALL a new generator/regulator assembly. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. D2 CHECK THE INTEGRITY OF THE S CIRCUIT 4 (WH/BK) Key in OFF position. Connect: Generator C102a http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 83/110
Key in START position. With the engine running at approximately 2,000 rpm, measure the voltage between generator S terminal C102b-1, circuit 4 (WH/BK) (back-probed), harness side and ground. Fig 76: Checking The Integrity Of The S Circuit 4 (WH/BK) Is the voltage greater than 5 volts? YES : INSTALL a new regulator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. Pinpoint Test E: The Charging System Warning Indicator Is Off With The Ignition Switch In The RUN Position And The Engine Off Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation Under normal operation, the charging system warning indicator is on with the key in the ON position and the engine off. Possible Causes Bulb Circuitry Instrument cluster (IC) Voltage regulator Generator PINPOINT TEST E: THE CHARGING SYSTEM WARNING INDICATOR IS OFF WITH THE http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 84/110
IGNITION SWITCH IN THE RUN POSITION AND THE ENGINE OFF E1 CHECK THE CHARGING SYSTEM WARNING INDICATOR Key in OFF position. Disconnect: Generator C102a With the engine off, connect a fused (15A) jumper wire between generator C102a-1, circuit 904 (LG/RD), harness side and ground. Key in ON position. Is the charging system warning indicator illuminated? YES : INSTALL a new voltage regulator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : REFER to INSTRUMENT CLUSTER article for the diagnosis and testing of the IC. Pinpoint Test F: The Charging System Warning Indicator Flickers Or Is Intermittent Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation Under normal operation, the charging system warning indicator is on with the key in the ON position and the engine off. With the engine running, the charging system warning indicator is off. Possible Causes Corroded terminal(s) Fusible links Circuitry Voltage regulator Generator PINPOINT TEST F: THE CHARGING SYSTEM WARNING INDICATOR FLICKERS OR IS INTERMITTENT F1 CHECK FOR LOOSE CONNECTIONS Key in OFF position. Check all of the generator, battery, fusible links and power distribution connections for looseness, corrosion, loose or bent terminals, or loose eyelets. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 85/110
Are all of the connections clean and tight? YES : Go to F2. NO : REPAIR as necessary. TEST the system for normal operation. F2 CHECK THE A CIRCUIT 35 (OG/LB) CONNECTIONS Connect a fused (15A) jumper wire between generator C102a-3, circuit 35 (OG/LB) (back-probed), harness side and the positive battery terminal. Fig 77: Checking The A Circuit 35 (OG/LB) Connections Key in START position. With the engine running, note the charging system warning indicator operation. Does the charging system warning indicator flicker? YES : If gas engine, go to F3. If diesel engine, turn the key to the OFF position and Go to F4. NO : REPAIR the loose connection(s) in circuit 35 (OG/LB). TEST the system for normal operation. F3 INSPECT THE S TERMINAL Key in OFF position. Check the generator S terminal C102b to make sure it is correctly mated to the generator and making good contact with the S terminal on the generator. Is the S terminal seated correctly? YES : Go to F4. NO : REPAIR as necessary. TEST the system for normal operation. F4 CHECK THE GENERATOR BRUSHES http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 86/110
Remove the generator from the vehicle. Refer to GENERATOR AND REGULATOR article. Measure the resistance between the A and F terminals on the voltage regulator. Fig 78: Checking The Generator Brushes Is the resistance less than 5 ohms? YES : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : Go to F5. F5 CHECK FOR A GROUNDED SLIP RING Remove the voltage regulator. Refer to GENERATOR AND REGULATOR article. Measure the resistance between the generator slip rings. Fig 79: Checking For A Grounded Slip Ring Is the resistance greater than 10,000 ohms? YES : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 87/110
NO : INSTALL a new voltage regulator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. Pinpoint Test G: The Generator Is Noisy Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator is belt-driven by the engine accessory drive system. Possible Causes Accessory drive belt Loose bolts/brackets Generator/pulley PINPOINT TEST G: THE GENERATOR IS NOISY G1 CHECK FOR ACCESSORY DRIVE BELT NOISE AND LOOSE MOUNTING BRACKETS Key in OFF position. Check the accessory drive belt for damage and correct installation. Refer to ACCESSORY DRIVE article. Check the accessory mounting brackets and generator pulley for looseness or misalignment. Is the accessory drive OK? YES : Go to G2. NO : REPAIR as necessary. TEST the system for normal operation. G2 CHECK THE GENERATOR FOR EXCESSIVE ELECTRICAL NOISE Disconnect: Generator C102c Key in START position. With the engine running, determine if the generator is still noisy. Is the noise still present? YES : Go to G3. NO : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. G3 CHECK THE GENERATOR FOR MECHANICAL NOISE http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 88/110
Turn all of the accessories off. With the engine running, use a stethoscope or equivalent listening device to probe the generator for unusual mechanical noise. Is the generator the noise source? YES : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. NO : REFER to ENGINE SYSTEM - GENERAL INFORMATION article to diagnose the source of the engine noise. Pinpoint Test H: Radio Interference Refer to appropriate WIRING DIAGRAM ARTICLE, Charging System for schematic and connector information. Normal Operation The generator radio suppression equipment reduces interference transmitted through the speakers by the vehicle electrical system. Possible Causes Generator Circuitry In-vehicle entertainment system PINPOINT TEST H: RADIO INTERFERENCE H1 VERIFY THE GENERATOR IS THE SOURCE OF THE RADIO INTERFERENCE NOTE: If the original equipment manufactured (OEM) audio unit has been replaced with an aftermarket unit, the vehicle may not pass this test. Return the vehicle to OEM condition before following this pinpoint test. Key in START position. Start and run the engine. Tune the audio unit to a station where the interference is present. Key in OFF position. Disconnect: Generator C102c Key in START position. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 89/110
Component Tests Battery - Drain Tests With the engine running, determine if the interference is still present. Is the interference present with the generator disconnected? YES : REFER to INFORMATION AND ENTERTAINMENT SYSTEMS article for diagnosis and testing of the in-vehicle entertainment system. NO : INSTALL a new generator. REFER to GENERATOR AND REGULATOR article. TEST the system for normal operation. WARNING: Do not attempt this test on a lead-acid battery that has recently been recharged. Explosive gases may cause personal injury. Failure to follow these instructions may result in personal injury. CAUTION: To prevent damage to the meter, do not crank the engine or operate accessories that draw more than 10A. NOTE: No factory-equipped vehicle should have more than a 50 ma (0.050 amp) draw. NOTE: Many electronic modules draw 10 ma (0.010 amp) or more continuously. NOTE: Use an in-line ammeter between the negative battery post and its respective cable. NOTE: Typically, a drain of approximately 1 amp can be attributed to an engine compartment lamp, glove compartment lamp or an interior lamp staying on continually. Other component failures or wiring shorts are located by selectively pulling fuses to pinpoint the location of the current drain. When the current drain is found, the meter reading will fall to an http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 90/110
acceptable level. If the drain is still not located after checking all of the fuses, it is due to the generator. NOTE: To accurately test the drain on a battery, an in-line ammeter must be used. Use of a test lamp or voltmeter is not an accurate method due to the number of electronic modules. Check for current drains on the battery in excess of 50 ma (0.050 amp) with all of the electrical accessories off and the vehicle at rest for at least 40 minutes. Current drains can be tested with the following procedure: 1. Make sure the battery junction box (BJB) and central junction box (CJB) are accessible without turning on the interior or the underhood lights. 2. Drive the vehicle at least 5 minutes and over 48 km/h (30 mph) to turn on and activate the vehicle systems. 3. Allow the vehicle to sit with the key off for at least 40 minutes to allow the modules to time out/power down. 4. Connect a fused (10A) jumper wire between the negative battery cable and the negative battery post to prevent the modules from resetting and to catch capacitive drains. 5. Disconnect the negative battery cable from the negative battery post without breaking the connection of the jumper wire. NOTE: It is very important that continuity is not broken between the negative battery cable and the negative battery post when connecting the meter. If this happens, the entire procedure must be repeated. 6. Connect the battery tester between the negative battery cable and the post. The meter must be capable of reading milliamps and should have a 10 amp capability. NOTE: If the meter settings need to be switched or the test leads need to be moved to another jack, the jumper wire must be reinstalled to avoid breaking continuity. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 91/110
NOTE: Amperage draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference. NOTE: No factory-equipped vehicle should have more than a 50 ma (0.050 amp) draw. 7. Remove the jumper wire. 8. Note the amperage draw. The draw varies from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference. No factory-equipped vehicle should have more than a 50 ma draw (0.050 amp). 9. If the draw is found to be excessive, remove the fuses from the CJB one at a time and note the current reading. Do not reinstall the fuses until you have finished testing. To properly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located. 10. If the current draw is still excessive, remove the fuses from the BJB one at a time and note the current drop. Do not reinstall the fuses until you have finished testing. To properly isolate each of the circuits, all of the fuses may need to be removed and install one fuse, note the amperage draw, then remove the fuse and install the next fuse, until all of the circuits are checked. When the current level drops to an acceptable level after removing a fuse, the circuit containing the excessive draw has been located. 11. Check the Wiring Diagrams for any circuits that run from the battery without passing through the BJB/CJB. If the current draw is still excessive, disconnect these circuits until the draw is found. Also, disconnect the generator electrical connections if the draw can not be located. The generator may be internally shorted, causing the current drain. Generator On-Vehicle Tests CAUTION: To prevent damage to the generator, do not make the jumper wire connections except as directed. CAUTION: Do not allow any metal object to http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 92/110
come in contact with the housing and the internal diode cooling fins with the key in the ON or OFF positions. A short circuit may result and burn out the diodes. NOTE: Battery posts and cable clamps must be clean and tight for accurate meter indications. NOTE: Refer to the battery tester manual for complete directions for testing the charging system. 1. Turn off all of the lamps and the electrical components. 2. Place the transmission in NEUTRAL and apply the parking brake. 3. Carry out the Load Test and No Load Test according to the following component tests: Generator On-Vehicle Tests - Load Test 1. Switch the tester to the ammeter function. 2. Connect the positive and negative leads of the tester to the corresponding battery terminals. 3. Connect the current probe to the generator B+ output terminal, circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines). 4. With the engine running at approximately 2,000 rpm, adjust the tester load bank to determine the output of the generator. The generator output should be greater than the graph shown below. If not, refer back to the pinpoint test or Go to Symptom Chart. Fig 80: 3G (Gas), 70/115 amps http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 93/110
Fig 81: 6G (Diesel), 65/110 amps Fig 82: VR42 (Diesel), 95/140 amps Generator On-Vehicle Tests - No-Load Test 1. Switch the tester to the voltmeter function. 2. Connect the voltmeter positive lead to the generator B+ terminal, circuit 36 (YE/WH) (gas engines) / circuit 1119 (RD) (diesel engines) and the negative lead to ground. 3. Turn all of the electrical accessories off. 4. With the engine running at approximately 2,000 rpm, check the generator output voltage. The voltage should be between 13.2 and 15.5 volts. If not, refer back to the pinpoint test or Go to Symptom Chart. DIAGNOSTIC TESTS Generator Refer to CHARGING SYSTEM - GENERAL INFORMATION article. REMOVAL AND INSTALLATION Generator - 6.0L Diesel, Single Generator http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 94/110
Fig 83: Identifying Single Generator - 6.0L Diesel (With Torque Specifications) Item Part Number Description 1 W705790-S901 Generator B+ terminal nut 2 - Generator B+ terminal (part of 12B637) 3 - Generator electrical connector (part of 12B637) 4 6B209 Accessory drive belt tensioner 5 86280 Accessory drive belt 6 N606068 Generator bolts (3 required) 7 10300 Generator REMOVAL AND INSTALLATION NOTE: Single generator is shown; primary generator on the dual generator vehicle is similar. 1. Disconnect the batteries. For additional information, refer to BATTERY, MOUNTING AND CABLES article. http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 95/110
2. Remove the cooling fan. For additional information, refer to ENGINE COOLING article. 3. Remove the nut and position the generator B+ terminal aside. 1. To install, tighten to 10 Nm (89 lb-in). 4. Disconnect the generator electrical connector. 5. Rotate the accessory drive belt tensioner clockwise and remove the drive belt from the generator pulley. 6. Remove the 3 bolts and the generator. 1. To install, tighten to 47 Nm (35 lb-ft). 7. To install, reverse the removal procedure. Generator - 6.0L Diesel, Dual Generator Fig 84: Identifying Dual Generator - 6.0L Diesel (With Torque Specifications) Item Part Number Description 1 6B209 Accessory drive belt tensioner 2 86280 Accessory drive belt 3 W705790-S901 Generator B+ terminal nut http://www1.prodemand.com/print/index?content=tabs&module=true&tab=true&terms=true&ymms=false&classname= 96/110