DIAGNOSIS AND TESTING

412-00-1 Climate Control System - General Information 412-00-1 DIAGNOSIS AND TESTING Climate Control System Refer to Wiring Diagrams Cell 54, Air Conditioner/Heater for schematic and connector information. Special Tool(s) Radiator Pressure Tester 014-R1072 or equivalent Fluke 77 III Automotive Meter 105-R0056 or equivalent Special Tool(s) Vacuum Pump Kit 416-D002 (D95L-7559-A) or equivalent Worldwide Diagnostic System (WDS) 418-F224, New Generation STAR (NGS) Tester 418-F052, or equivalent scan tool R-134a Manifold Gauge Set 176-R032A or equivalent H10PM Refrigerant Leak Detector with Battery 216-00001 or equivalent Refrigerant Pressure Line Connector 412-093 (T94P-19623-E) A/C Fittings Set 412-DS028 (014-00333, D93L-19703-B) or equivalent Copyright 2002, Ford Motor Company Last updated: 5/16/2006

412-00-2 Climate Control System - General Information 412-00-2 DIAGNOSIS AND TESTING Vacuum Schematic Manual Climate Control Item Part Number Description Item Part Number Description 1 18A318 Vacuum control motor, 7 Air inlet duct door (full panel/defrost door vacuum position) 2 Panel/defrost door (full 8 Outside air inlet vacuum position) 9 18A318 Vacuum control motor, air 3 Defrost airflow inlet door 4 Side window demister airflow 10 Recirculated air inlet 5 18B545 Temperature blend door (full 11 19805 Blower motor heat position) 12 Vacuum to emission control 6 19860 A/C evaporator core

412-00-3 Climate Control System - General Information 412-00-3 DIAGNOSIS AND TESTING Item Part Number Description 13 Vacuum from the engine intake manifold 14 A/C vacuum check valve (part of 19C828) 15 19A566 A/C vacuum reservoir tank and bracket 16 19B888 A/C-heater function selector switch 17 18476 Heater core 18 Panel/floor door (full vacuum position) 19 Floor airflow Vacuum Connector End View Manual Climate Control 20 18A318 Vacuum control motor, panel/floor door Port Hose Color Function 21 Panel airflow 1 White Air inlet door 2 Yellow Panel/floor door 3 Black Vacuum source 4 t used 5 Blue Panel/floor door 6 Red Panel/defrost door VACUUM APPLICATION CHART MANUAL CLIMATE CONTROL Function Selector Switch Position Switch MAX PNL/ PNL/ FLR/ Port Color Function A/C A/C VENT OFF FLR FLOOR DEF DEF 1 White Recirc/ fresh V NV NV V NV NV NV NV 2 Yellow Full floor NV NV NV V NV V NV NV 3 Black Vacuum source V V V V V V V V 5 Blue Panel/ floor NV NV NV V V V V NV 6 Red Panel/ defrost V V V NV V NV NV NV V = Vacuum NV = Vacuum

412-00-4 Climate Control System - General Information 412-00-4 DIAGNOSIS AND TESTING Vacuum Schematic Electronic Automatic Temperature Control Item Part Number Description Item Part Number Description 1 18A318 Vacuum control motor 7 Air inlet door (full vacuum panel/defrost door position) 2 Panel/defrost door (full 8 Outside air inlet vacuum position) 9 18A318 Vacuum control motor air 3 Defrost airflow inlet door 4 Side window demister airflow 10 Recirculated air inlet 5 18B545 Temperature blend door (full 11 19805 Blower motor heat position) 12 Vacuum to emission control 6 19860 A/C evaporator core

412-00-5 Climate Control System - General Information 412-00-5 DIAGNOSIS AND TESTING Item Part Number Description 13 Vacuum from the engine intake manifold 14 A/C vacuum check valve (part of 19C828) 15 19A566 A/C vacuum reservoir tank and bracket 16 19980 Electronic automatic temperature control module 17 18476 Heater core 18 Panel/floor door (full vacuum position) 19 Floor airflow Vacuum Connector End View Electronic Automatic Temperature Control 20 18A318 Vacuum control motor panel/floor door Item Part Number Description 21 Panel airflow 1 t used Vacuum Applications Chart Electronic Automatic Temperature Control Switch Port Color Function 2 Red Panel/defrost door 3 Blue Panel/floor door 4 Black Source vacuum 5 White Air inlet door 6 Yellow Panel/floor door Manual Override Selector Buttons MAX PNL/ FLR/ OFF A/C VENT FLR FLOOR DEF DEF 2 Red Panel/ defrost NV V V V NV NV NV 3 Blue Panel/floor (partial) NV NV NV V V V NV 4 Black Source V V V V V V V 5 White Outside/ recirc V V NV NV NV NV NV 6 Yellow Full floor NV NV NV NV V NV NV V = vacuum 2. Visually inspect for obvious signs of NV = no vacuum mechanical or electrical damage. Inspection and Verification 1. Verify the customer concern by operating the climate control system to duplicate the condition.

412-00-6 Climate Control System - General Information 412-00-6 DIAGNOSIS AND TESTING Visual Inspection Chart 7. Carry out the DATA LINK DIAGNOSTICS Mechanical Electrical test. If the scan tool responds with: Loose, missing or Fuse(s) CKT 914, CKT 915, or CKT 70 = ALL damaged A/C Blower motor (19805) ECUS NO RESP/NOT EQUIP, refer to compressor drive belt inoperative Section 418-00 to diagnose the network Loose or disconnected A/C compressor (19703) concern. A/C clutch (19D798) inoperative Loose, misrouted or Circuitry open/shorted If the powertrain control module (PCM) is damaged vacuum lines a Disconnected, loose not listed for a communication concern, turn Broken or leaking fitting, or incorrectly the A/C controls to OFF and execute the vacuum control motor installed electrical self-test diagnostics for the PCM. (18A318) a connectors and pins Discharged A/C system If the EATC module is not listed for a Broken or leaking communication concern, execute self-test refrigerant lines diagnostics for the EATC module. a A leak in the vacuum control circuit may occur 8. If any PCM or EATC DTCs are retrieved, and during acceleration (slow leak), may exist at all are related to the concern, go to the Powertrain times (large leak), and may exist only when specific Control Module Diagnostic Trouble Code functions are selected (indicating a leak in that portion of the circuit). The vacuum hoses used in (DTC) Index or the Electronic Automatic the passenger compartment control circuit are Temperature Control (EATC) Module constructed from PVC plastic material. The vacuum Diagnostic Trouble Code (DTC) Index to hoses used in the engine compartment are continue diagnostics. constructed of Hytrel. Because of the materials used, never pinch the vacuum hoses off during 9. If no DTCs related to the concern are retrieved, diagnosis to locate a leak. A wood golf tee can be GO to Symptom Chart to continue diagnostics. used as a plug when it is necessary to plug one end 10. If the EATC module cannot be accessed by the of the vacuum hose for leak test purposes. scan tool, GO to Pinpoint Test E. 3. As pinpoint tests and measurements are being Electronic Automatic Temperature Control performed, be sure to inspect for any Module Self-Test disconnected, loose fitting, or incorrectly installed component, module and in-line The EATC module self-test will not detect electrical connectors and pins. concerns associated with data link messages like engine coolant temperature or vehicle speed 4. If an obvious cause for an observed or reported signals. A scan tool must be used to retrieve these concern is found, correct the cause (if possible) concerns. before proceeding to the next step. The EATC module self-test will detect concerns 5. If the cause is not visually evident, connect a in the system control functions and will display scan tool to the data link connector (DLC) and hard diagnostic trouble codes (DTCs) in addition select the vehicle to be tested from the scan to intermittent diagnostic trouble codes for tool menu. If the scan tool does not concerns that occur during system operation. The communicate with the vehicle: vehicle interior temperature should be between check that the program card is correctly 4-32 C (40-90 F) when performing the self-test. installed. If the temperatures are not within the specified check the connections to the vehicle. ranges, false in-car temperature sensor DTCs will be displayed. check the ignition switch position. The self-test can be initiated at any time. rmal 6. If the scan tool still does not communicate with operation of the system stops when the self-test is the vehicle, refer to the scan tool operating activated. manual.

412-00-7 Climate Control System - General Information 412-00-7 DIAGNOSIS AND TESTING To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed. If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given. If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation. Always exit the self-test before powering the system down (system turned OFF). Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs. Powertrain Control Module Diagnostic Trouble Code (DTC) Index DTC Description Action to Take P1460 Wide open throttle Refer to the A/C primary circuit Powertrain malfunction Control/Emissions Diagnosis (PC/ED) manual. To exit self-test and retain all intermittent DTCs, P1464 A/C demand out of Refer to the push the blue (cooler temperature) button. The self-test range Powertrain control will exit self-test, retain all intermittent Control/Emissions DTCs and then turn OFF (display blank). Diagnosis (PC/ED) manual. To exit self-test and clear all DTCs, press the P1469 Low A/C cycling Refer to the DEFROST button. The vacuum fluorescent period Powertrain display window will show 888 and all function Control/Emissions symbols for one second. Then, the EATC control Diagnosis (PC/ED) assembly will turn OFF (display blank) and all manual. DTCs will be cleared. Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index EATC (Hard) EATC (Intermittent) DTC Self-Test Faults Run-Time Faults Description Action to Take B1249 024 022/25 Blend door failure or GO to Pinpoint Test A. short B1251 031 N/A A/C in-car temperature GO to Pinpoint Test B. sensor (19D888) open circuit B1253 030 N/A A/C in-car temperature GO to Pinpoint Test B. sensor (19D888) short to ground B1255 041 043 A/C ambient GO to Pinpoint Test C. temperature (19E702) sensor open circuit B1257 040 042 A/C ambient GO to Pinpoint Test C. temperature sensor (19E702) short to ground B1261 050 052 A/C solar radiation GO to Pinpoint Test D. sensor (19E663) circuit short to ground

412-00-8 Climate Control System - General Information 412-00-8 DIAGNOSIS AND TESTING Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index EATC (Hard) EATC (Intermittent) DTC Self-Test Faults Run-Time Faults Description Action to Take U1073 N/A Standard Corporate Refer to the Powertrain Protocol (SCP) invalid Control/Emissions or missing data for Diagnosis (PC/ED) engine coolant manual. U1341 N/A N/A Standard Corporate Refer to the Powertrain Protocol (SCP) invalid Control/Emissions data for vehicle speed Diagnosis (PC/ED) manual. Symptom Chart Symptom Chart Condition Possible Sources Action communication with the Circuitry short/open. GO to Pinpoint Test E. electronic automatic EATC module temperature control (EATC) communication network. module (19980) The EATC system is Circuitry short/open. GO to Pinpoint Test F. inoperative, intermittent or Input sensor(s)/erratic input incorrect operation signals. Charging system. Automatic temperature control sensor hose and elbow (19D888). Incorrect/erratic direction of vacuum to the A/C GO to Pinpoint Test G. airflow from outlet manual control (19980). climate control Function selector switch (19B888). Vacuum hose/kinked/pinched. Airflow door binding/stuck. Vacuum control motor (18A318). A/C vacuum check valve (19A563). A/C vacuum reservoir tank and bracket (19A566). Vacuum actuator arm not connected to the door crank. Heater control valve (18495) leaks vacuum.

412-00-9 Climate Control System - General Information 412-00-9 DIAGNOSIS AND TESTING Symptom Chart Condition Possible Sources Action Incorrect/erratic direction of vacuum to the A/C GO to Pinpoint Test H. airflow from outlet EATC control (19980). Function selector switch (19B888). Vacuum hose/kinked/pinched. Airflow door binding/stuck. Vacuum control motor (18A318). A/C vacuum check valve (19A563). A/C vacuum reservoir tank and bracket (19A566). Vacuum actuator arm not connected to the door crank. Heater control valve (18495) leaks vacuum. Insufficient, erratic, or no Low engine coolant level. GO to Pinpoint Test I. heat Engine overheating. Plugged or partially plugged heater core (18476). Temperature blend door binding/stuck. Temperature blend door actuator (19E616). Incorrect heater control valve (18495) operation. The air conditioning (A/C) is Fuse(s). GO to Pinpoint Test J. inoperative/does not operate Circuitry short/open. correctly A/C cycling switch (19E561). A/C system discharged/low charge. A/C pressure cutoff switch (19D594). A/C control (19980). The air conditioning (A/C) is Circuitry short/open. GO to Pinpoint Test K. always on A/C cycling switch (19E561). Function control switch (19B888). operation in all the Temperature blend door GO to Pinpoint Test L. temperature settings actuator control (19D816). manual climate control Temperature blend door. Temperature blend door actuator motor (19E616). Circuitry open/shorted. The blower motor is Circuitry open/shorted. GO to Pinpoint Test M. inoperative manual climate A/C blower motor switch control (19986). A/C blower motor resistor (19A706). A/C blower motor (19805). The blower motor is Circuitry short/open. GO to Pinpoint Test N. inoperative EATC Blower motor relay (14N089). A/C blower motor (19805). A/C blower motor speed control (19E624).

412-00-10 Climate Control System - General Information 412-00-10 DIAGNOSIS AND TESTING Symptom Chart Condition Possible Sources Action operation in high blower A/C blower motor resistor GO to Pinpoint Test O. setting manual climate (19A706). control A/C blower motor switch (19986). operation in lower speeds Circuitry short/open. GO to Pinpoint Test P. manual climate control A/C blower motor resistor (19A706). A/C blower motor switch (19986). Blower motor relay (14N089). The blower motor operates Circuitry short. GO to Pinpoint Test Q. continuously in high speed A/C blower motor resistor manual climate control (19A706). A/C blower motor switch (19986). Blower motor relay (14N089). The blower motor operates Circuitry short/open. GO to Pinpoint Test R. continuously in high speed A/C blower motor speed EATC control (19E624). EATC module (19980). The temperature set point Fuse(s). CHECK circuit 729 (RD/WH) does not repeat after turning Circuitry short/open. for a short or open and repair the ignition switch OFF EATC module (19980). as necessary. If okay, EATC INSTALL a new EATC module. The temperature display will EATC module. PRESS the MAX A/C and not switch between Celsius DEFROST buttons and Fahrenheit EATC simultaneously for at least 0.75 second. If the temperature display does not switch between Celsius and Fahrenheit, INSTALL a new EATC module. The outside air temperature Ambient temperature sensor. CARRY OUT the ambient display is inaccurate EATC module. temperature sensor component test in this section. If the ambient temperature sensor is good, INSTALL a new EATC module. Pinpoint Tests A1 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK THE BLEND DOOR ACTUATOR CLOCKWISE OPERATION Disconnect: EATC Module C228a and C228b. Key in ON position.

412-00-11 Climate Control System - General Information 412-00-11 DIAGNOSIS AND TESTING A1 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK THE BLEND DOOR ACTUATOR CLOCKWISE OPERATION Connect a fused jumper wire between EATC module C228a pin 13, circuit 250 (OG) and EATC module C228b pin 2, circuit 729 (RD/WH). Connect a second fused jumper wire between EATC module C228a pin 26, circuit 249 (DB/LG) and EATC module C228b pin 3, circuit 57 (BK). A2 GO to A2. Does the air bypass door actuator motor move in the closed direction? GO to A3. CHECK THE BLEND DOOR ACTUATOR COUNTERCLOCKWISE OPERATION Connect a fused jumper wire between EATC module C228a pin 26, circuit 249 (DB/LG) and EATC module C228b pin 2, circuit 729 (RD/WH). Connect a second fused jumper wire between EATC module C228a pin 13, circuit 250 (OG) and EATC module C228b pin 3, circuit 57 (BK). A3 GO to A9. Does the actuator motor move in the clockwise direction? GO to A3. CHECK THE ACTUATOR CLOCKWISE OPERATION Remove the door actuator and disengage the actuator drive shaft from the actuator door. Refer to Section 412-04.

412-00-12 Climate Control System - General Information 412-00-12 DIAGNOSIS AND TESTING A3 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK THE ACTUATOR CLOCKWISE OPERATION Connect a fused jumper wire between EATC module C228a pin 13, circuit 250 (OG) and EATC module C228b pin 2, circuit 729 (RD/WH). Connect a second fused jumper wire between EATC module C228a pin 26, circuit 249 (DB/LG) and EATC module C228b pin 3, circuit 57 (BK). A4 INSPECT for binding, broken door or linkage. If no condition is found, INSTALL a new door actuator. REFER to Section 412-04. TEST the system for normal operation. Does the air bypass door actuator motor move in the closed direction? GO to A4. CHECK THE ACTUATOR COUNTERCLOCKWISE OPERATION Connect a fused jumper wire between EATC module C228a pin 26, circuit 249 (DB/LG) and EATC module C228b pin 2, circuit 729 (RD/WH). Connect a second fused jumper wire between EATC module C228a pin 13, circuit 250 (OG) and EATC module C228b pin 3, circuit 57 (BK). INSPECT for binding or broken door or linkage. If no condition is found, INSTALL a new door actuator. REFER to Section 412-04. TEST the system for normal operation. Does the actuator motor move in the clockwise direction? GO to A5. A5 CHECK CIRCUITS 249 (DB/LG) AND 250 (OG) FOR A SHORT TO GROUND Disconnect: Temperature Blend Door Actuator C289.

412-00-13 Climate Control System - General Information 412-00-13 DIAGNOSIS AND TESTING PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT A5 CHECK CIRCUITS 249 (DB/LG) AND 250 (OG) FOR A SHORT TO GROUND Measure the resistance between EATC module C228a pin 26, circuit 249 (DB/LG) and ground. Measure the resistance between EATC module C228a pin 13, circuit 250 (OG) and ground. A6 GO to A6. REPAIR the affected circuit for a short to ground. TEST the system for normal Are the resistances greater than 10,000 ohms? operation. CHECK CIRCUITS 249 (DB/LG) AND 250 (OG) FOR A SHORT TO POWER Key in ON position. Measure the voltage between EATC module C228a pin 26, circuit 249 (DB/LG) and ground. Measure the voltage between EATC module C2286 pin 13, circuit 250 (OG) and ground. A7 REPAIR the affected circuit for a short to power. TEST the system for normal operation. Is voltage present? GO to A7. CHECK CIRCUITS 249 (DB/LG) AND 250 (OG) FOR AN OPEN

412-00-14 Climate Control System - General Information 412-00-14 DIAGNOSIS AND TESTING A7 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK CIRCUITS 249 (DB/LG) AND 250 (OG) FOR AN OPEN Measure the resistance between EATC module C228b pin 26, circuit 249 (DB/LG) and the temperature blend door actuator C289 pin 8, circuit 249 (DB/LG). Measure the resistance between EATC module C2286 pin 13, circuit 250 (OG) and the temperature blend door actuator C289 pin 7, circuit 250 (OG). A8 GO to A8. REPAIR the affected circuit for an open. Are the resistances less than 5 ohms? TEST the system for normal operation. CHECK CIRCUIT 250 (OG) AND 249 (DB/LG) FOR A SHORT TOGETHER Measure the resistance between EATC module C228a pin 13, circuit 250 (OG) and EATC module C228a pin 26, circuit 249 (DB/LG). A9 INSTALL a new door actuator. REFER to Section 412-04. TEST the system for normal operation. REPAIR circuit 250 (OG) and circuit 249 (DB/LG) for a short together. TEST the Is the resistance less than 5 ohms? system for normal operation. CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE

412-00-15 Climate Control System - General Information 412-00-15 DIAGNOSIS AND TESTING A9 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK THE FEEDBACK POTENTIOMETER TOTAL RESISTANCE Measure the resistance between EATC module C228b pin 6, circuit 243 (LG/OG) and EATC module C228a pin 9, circuit 247 (WH/YE). A10 GO to A12. If the resistance is greater than 6,000 ohms, GO to A10. If the resistance is less than 5,000 ohms, Is the resistance between 5,000 and 6,000 ohms? GO to A11. CHECK CIRCUITS 243 (LG/OG) AND 247 (WH/YE) FOR AN OPEN Disconnect: Temperature Blend Door Actuator C289. Measure the resistance between EATC module C228b pin 6, circuit 243 (LG/OG) and the temperature blend door actuator C289 pin 5, circuit 243 (LG/OG). Measure the resistance between EATC module C228a pin 9, circuit 247 (WH/YE) and the temperature blend door actuator C289 pin 6, circuit 247 (WH/YE). INSTALL a new temperature blend door actuator. REFER to Section 412-04. TEST the system for normal operation. REPAIR the affected circuit for an open. Are the resistances less than 5 ohms? TEST the system for normal operation. A11 CHECK CIRCUIT 247 (WH/YE) FOR A SHORT TO CIRCUIT 243 (LG/OG) Disconnect: Temperature Blend Door Actuator C289.

412-00-16 Climate Control System - General Information 412-00-16 DIAGNOSIS AND TESTING PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT A11 CHECK CIRCUIT 247 (WH/YE) FOR A SHORT TO CIRCUIT 243 (LG/OG) Measure the resistance between EATC module C228a pin 9, circuit 247 (WH/YE) and EATC module C228b pin 6, circuit 243 (LG/OG). A12 INSTALL a new temperature blend door actuator (19E616). REFER to Section 412-04. TEST the system for normal operation. REPAIR circuits 247 (WH/YE) for a short to circuits 243 (LG/OG). TEST the system Is the resistance greater than 10,000 ohms? for normal operation. CHECK POTENTIOMETER LOW SIDE RESISTANCE Drive the actuator to the full clockwise position. Refer to A1. Measure the resistance between EATC module C228b pin 6, circuit 243 (LG/OG) and EATC module C228b pin 18, circuit 246 (VT). A13 GO to A15. If the resistance is greater than 3,000 ohms, GO to A13. If the resistance is less than 250 ohms, Is the resistance between 250 and 3,000 ohms? GO to A14. CHECK CIRCUIT 246 (VT) FOR AN OPEN Disconnect: Temperature Blend Door Actuator C289.

412-00-17 Climate Control System - General Information 412-00-17 DIAGNOSIS AND TESTING A13 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK CIRCUIT 246 (VT) FOR AN OPEN Measure the resistance between EATC module C228b pin 18, circuit 246 (VT) and the temperature blend door actuator C289 pin 1, circuit 246 (VT). A14 INSTALL a new temperature blend door actuator (19E616). REFER to Section 412-04. TEST the system for normal operation. REPAIR circuit 246 (VT) for an open. Is the resistance less than 5 ohms? TEST the system for normal operation. CHECK CIRCUIT 243 (LG/OG) AND CIRCUIT 246 (VT) FOR A SHORT TOGETHER Disconnect: Temperature Blend Door Actuator C289. Measure the resistance between EATC module C228b pin 6, circuit 243 (LG/OG) and EATC module C228b pin 18, circuit 246 (VT). A15 INSTALL a new temperature blend door actuator (19E616). REFER to Section 412-04. TEST the system for normal operation. REPAIR circuits 243 (LG/OG) and circuit 246 (VT) for a short together. TEST the Is the resistance greater than 10,000 ohms? system for normal operation. CHECK POTENTIOMETER HIGH SIDE RESISTANCE Measure the resistance between EATC module C228b pin 18, circuit 246 (VT) and EATC module C228a pin 9, circuit 247 (WH/YE). GO to A17. If the resistance is greater than 6,000 ohms, INSTALL a new temperature blend door actuator. REFER to Section 412-04. TEST the system for normal operation. If the resistance is less than 3,000 ohms, Is the resistance between 3,000 and 6,000 ohms? GO to A16.

412-00-18 Climate Control System - General Information 412-00-18 DIAGNOSIS AND TESTING A16 PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT CHECK CIRCUIT 247 (WH/YE) AND CIRCUIT 246 (VT) FOR A SHORT TOGETHER Disconnect: Temperature Blend Door Actuator C289. Measure the resistance between EATC module C228a pin 9, circuit 247 (WH/YE) and EATC module C228b pin 18, circuit 246 (VT). A17 INSTALL a new temperature blend door actuator (19E616). REFER to Section 412-04. TEST the system for normal operation. REPAIR circuits 246 (VT) for a short to circuit 247 (WH/YE). TEST the system for Is the resistance greater than 10,000 ohms? normal operation. CHECK CIRCUITS 243 (LG/OG) AND 246 (VT) FOR A SHORT TO GROUND Disconnect: Temperature Blend Door Actuator C289. Measure the resistance between EATC module C228b pin 6, circuit 243 (LG/OG) and ground. Measure the resistance between EATC module C228b pin 18, circuit 246 (VT) and ground. GO to A18. REPAIR the affected circuit 243 (LG/OG) or circuit 246 (VT) for a short to ground. Are the resistances greater than 10,000 ohms? TEST the system for normal operation. A18 CHECK CIRCUITS 243 (LG/OG) 246 (VT) AND 247 (WH/YE) FOR A SHORT TO POWER Key in ON position.

412-00-19 Climate Control System - General Information 412-00-19 DIAGNOSIS AND TESTING PINPOINT TEST A: DTC B1249 BLEND DOOR FAILURE OR SHORT A18 CHECK CIRCUITS 243 (LG/OG) 246 (VT) AND 247 (WH/YE) FOR A SHORT TO POWER Measure the voltage between EATC module C228b pin 6, circuit 243 (LG/OG), EATC module C228b pin 18, circuit 246 (VT) and EATC module C228a pin 9, circuit 247 (WH/YE) and ground. REPAIR the affected circuit for a short to power. TEST the system for normal operation. INSPECT for a broken door or linkage. If no condition is found, INSTALL a new EATC module. REFER to Section 412-04. Is voltage present? TEST the system for normal operation. PINPOINT TEST B: DTC B1251 OR DTC B1253 A/C IN-CAR TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND B1 CHECK THE SENSOR RESISTANCE Disconnect: In-Car Temperature Sensor C233. Measure the resistance between the in-car temperature sensor terminals. B2 GO to B2. Is the resistance within the specified values for these temperature ranges: 10-20 C (50-68 F), 37,000-58,000 ohms; INSTALL a new in-car temperature sensor 20-30 C (68-86 F), 24,000-37,000 ohms; 30-40 C (86-104 F), (19D888). TEST the system for normal 16,000-24,000 ohms? operation. CHECK THE EATC SENSOR OUTPUT VOLTAGE Key in ON position. Press the AUTOMATIC button.

412-00-20 Climate Control System - General Information 412-00-20 DIAGNOSIS AND TESTING PINPOINT TEST B: DTC B1251 OR DTC B1253 A/C IN-CAR TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND B2 CHECK THE EATC SENSOR OUTPUT VOLTAGE Measure the voltage between the in-car temperature sensor C233, circuit 790 (WH/OG) and circuit 470 (PK/BK). B3 INSTALL a new EATC module (19980). TEST the system for normal operation. If diagnosing DTC B1251, GO to B3. Is the voltage between 4.7 and 5.1 volts? If diagnosing DTC B1253, GO to B5. CHECK CIRCUIT 790 (WH/OG) FOR AN OPEN Disconnect: EATC Module C228a. Measure the resistance between the EATC module C228a pin 21, circuit 790 (WH/OG) and the in-car temperature sensor C233, circuit 790 (WH/OG). B4 GO to B4. REPAIR circuit 790 (WH/OG) for an open. Is the resistance less than 5 ohms? TEST the system for normal operation. CHECK CIRCUIT 470 (PK/BK) FOR AN OPEN NOTE: When performing tests, allow time for resistance measurement to stabilize. Disconnect: EATC Module C228b.

412-00-21 Climate Control System - General Information 412-00-21 DIAGNOSIS AND TESTING PINPOINT TEST B: DTC B1251 OR DTC B1253 A/C IN-CAR TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND B4 CHECK CIRCUIT 470 (PK/BK) FOR AN OPEN Measure the resistance between the EATC module C228b pin 4, circuit 470 (PK/BK) and the in-car temperature sensor C233, circuit 470 (PK/BK). INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 470 (PK/BK) for an open. Is the resistance less than 5 ohms? TEST the system for normal operation. B5 CHECK CIRCUIT 790 (WH/OG) FOR A SHORT TO CIRCUIT 470 (PK/BK) Disconnect: EATC Module C228a. Measure the resistance between the in-car temperature sensor C233, circuit 790 (WH/OG) and circuit 470 (PK/BK). B6 GO to B6. REPAIR circuit 790 (WH/OG) for a short to circuit 470 (PK/BK). TEST the system Is the resistance greater than 10,000 ohms? for normal operation. CHECK CIRCUIT 790 (WH/OG) FOR A SHORT TO GROUND Measure the resistance between the EATC module C228a pin 21, circuit 790 (WH/OG) and ground. INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 790 (WH/OG) for a short to ground. TEST the system for normal Is the resistance greater than 10,000 ohms? operation.

412-00-22 Climate Control System - General Information 412-00-22 DIAGNOSIS AND TESTING C1 PINPOINT TEST C: DTC B1255 OR DTC B1257 A/C AMBIENT TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND CHECK THE AMBIENT TEMPERATURE SENSOR RESISTANCE Disconnect: Ambient Temperature Sensor C132. Measure the resistance between the ambient temperature sensor terminals. C2 GO to C2. Is the resistance within the specified values for these temperature ranges: 10-20 C (50-68 F), 37,000-58,000 ohms; INSTALL a new ambient air temperature 20-30 C (68-86 F), 24,000-37,000 ohms; 30-40 C (86-104 F), sensor (19E702). TEST the system for 16,000-24,000 ohms? normal operation. CHECK THE EATC MODULE OUTPUT VOLTAGE Key in ON position. Press the AUTOMATIC button. Measure the voltage between the ambient temperature sensor C132, circuit 767 (LB/OG) and circuit 470 (PK/BK). C3 INSTALL a new EATC module (19980). TEST the system for normal operation. If diagnosing DTC B1255, GO to C3. Is the voltage between 4.7 and 5.1 volts? If diagnosing DTC B1257, GO to C5. CHECK CIRCUIT 767 (LB/OG) FOR AN OPEN Disconnect: EATC Module C228b.

412-00-23 Climate Control System - General Information 412-00-23 DIAGNOSIS AND TESTING C3 PINPOINT TEST C: DTC B1255 OR DTC B1257 A/C AMBIENT TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND CHECK CIRCUIT 767 (LB/OG) FOR AN OPEN Measure the resistance between the EATC module C228b pin 7, circuit 767 (LB/OG) and the ambient temperature sensor C132, circuit 767 (LB/OG). C4 GO to C4. REPAIR circuit 767 (LB/OG) for an open. Is the resistance less than 5 ohms? TEST the system for normal operation. CHECK CIRCUIT 470 (PK/BK) FOR AN OPEN Measure the resistance between the EATC module C228b pin 4, circuit 470 (PK/BK) and the ambient temperature sensor C132, circuit 470 (PK/BK). INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 470 (PK/BK) for an open. Is the resistance less than 5 ohms? TEST the system for normal operation. C5 CHECK CIRCUIT 767 (LB/OG) FOR A SHORT TO CIRCUIT 470 (PK/BK) Disconnect: EATC Module C228b.

412-00-24 Climate Control System - General Information 412-00-24 DIAGNOSIS AND TESTING PINPOINT TEST C: DTC B1255 OR DTC B1257 A/C AMBIENT TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND C5 CHECK CIRCUIT 767 (LB/OG) FOR A SHORT TO CIRCUIT 470 (PK/BK) Measure the resistance between the ambient temperature sensor C132, circuit 767 (LB/OG) and circuit 470 (PK/BK). C6 GO to C6. REPAIR circuit 767 (LB/OG) for a short to ground. TEST the system for normal Is the resistance greater than 10,000 ohms? operation. CHECK CIRCUIT 767 (LB/OG) FOR A SHORT TO GROUND Measure the resistance between the EATC module C228b pin 7, circuit 767 (LB/OG) and ground. INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 767 (LB/OG) for a short to ground. TEST the system for normal Is the resistance greater than 10,000 ohms? operation. PINPOINT TEST D: DTC B1261 A/C SOLAR RADIATION SENSOR CIRCUIT SHORT TO GROUND D1 CHECK THE SOLAR RADIATION SENSOR RESISTANCE Disconnect: Solar Radiation Sensor C286.

412-00-25 Climate Control System - General Information 412-00-25 DIAGNOSIS AND TESTING D1 PINPOINT TEST D: DTC B1261 A/C SOLAR RADIATION SENSOR CIRCUIT SHORT TO GROUND CHECK THE SOLAR RADIATION SENSOR RESISTANCE NOTE: Connect the ground lead of the multimeter to ground on the sensor, circuit 470 (PK/BK). Measure the resistance between the solar radiation sensor terminals. D2 GO to D2. INSTALL a new solar radiation sensor (19E663). TEST the system for normal Is the resistance greater than 0 ohms? operation. CHECK THE SOLAR RADIATION SENSOR REFERENCE VOLTAGE Key in ON position. Press the AUTOMATIC button. Measure the voltage between the solar radiation sensor C286, circuit 468 (BN) and circuit 470 (PK/BK). INSTALL a new EATC module (19980). TEST the system for normal operation. Is the voltage between 4.7 and 5.1 volts? GO to D3. D3 CHECK CIRCUIT 468 (BN) FOR A SHORT TO CIRCUIT 470 (PK/BK). Disconnect: EATC Module C228b.

412-00-26 Climate Control System - General Information 412-00-26 DIAGNOSIS AND TESTING PINPOINT TEST D: DTC B1261 A/C SOLAR RADIATION SENSOR CIRCUIT SHORT TO GROUND D3 CHECK CIRCUIT 468 (BN) FOR A SHORT TO CIRCUIT 470 (PK/BK). Measure the resistance between the solar radiation sensor C286, circuit 468 (BN) and circuit 470 (PK/BK). D4 GO to D4. REPAIR circuit 468 (BN) for a short to Is the resistance greater than 10,000 ohms? circuit 470 (PK/BK). CHECK CIRCUIT 468 (BN) FOR A SHORT TO GROUND Measure the resistance between the EATC module C228b pin 20, circuit 468 (BN) and ground. INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 468 (BN) for a short to ground. TEST the system for normal Is the resistance greater than 10,000 ohms? operation. PINPOINT TEST E: NO COMMUNICATION WITH THE ELECTRONIC AUTOMATIC TEMPERATURE CONTROL MODULE E1 CHECK CIRCUIT 57 (BK) FOR AN OPEN Disconnect: EATC Module C228b.

412-00-27 Climate Control System - General Information 412-00-27 DIAGNOSIS AND TESTING E1 PINPOINT TEST E: NO COMMUNICATION WITH THE ELECTRONIC AUTOMATIC TEMPERATURE CONTROL MODULE CHECK CIRCUIT 57 (BK) FOR AN OPEN Measure the resistance between the EATC module C228b pin 3, circuit 57 (BK) and ground. GO to E2. REPAIR circuit 57 (BK) for an open. TEST Is the resistance less than 25 ohms? the system for normal operation. E2 CHECK CIRCUIT 729 (RD/WH) FOR B+ Measure the voltage between the EATC module C228b pin 2, circuit 729 (RD/WH) and ground. GO to E3. REPAIR circuit 729 (RD/WH) for an open. Is the voltage B+? TEST the system for normal operation. E3 CHECK CIRCUIT 296 (WH/VT) FOR B+ Key in ON position. Measure the voltage between the EATC module C228b pin 16, circuit 296 (WH/VT) and ground. REFER to Section 418-00 to diagnose a network concern. REPAIR circuit 296 (WH/VT) for an open. Is the voltage B+? TEST the system for normal operation.

412-00-28 Climate Control System - General Information 412-00-28 DIAGNOSIS AND TESTING PINPOINT TEST F: THE EATC SYSTEM IS INOPERATIVE, INTERMITTENT OR INCORRECT OPERATION F1 F2 VERIFY AUTOMATIC OPERATION Key in ON position. With engine running, press the AUTOMATIC button. GO to F2. Does AUTO and the selected temperature appear in the display window? GO to F11. PERFORM THE EATC MODULE SELF-TEST Carry out the EATC module self-test. Refer to the Electronic Automatic Temperature Control Module Self-Test in this section. Record the DTCs displayed, if any. F3 F4 F5 F6 F7 REFER to the Electronic Automatic Temperature Control (EATC) Module Diagnostic Trouble Code (DTC) Index. CARRY OUT the necessary diagnosis and REPAIR as required. Were any DTCs displayed as a result of the EATC self-test? GO to F3. CHECK THE VACUUM FLUORESCENT DISPLAY Exit self-test by pressing the DEFROST button. Observe the function symbols displayed on the vacuum fluorescent display. GO to F4. Is the display correct and complete without any missing elements? INSTALL a new EATC module (19980). TEST the system for normal operation. CHECK THE BLOWER MANUAL OVERRIDE OPERATION Slowly rotate the blower motor speed override control from LO to HI. GO to F5. Does the blower motor speed increase smoothly from low speed to high speed? If the blower motor is inoperative, GO to Pinpoint Test N. If the blower motor operates continuously in high speed, GO to Pinpoint Test R. VERIFY THE DEFROST OVERRIDE OPERATION Press the override button for DEFROST operation. Is outside air being discharged from the windshield GO to F6. defroster nozzle and the side window demisters? GO to Pinpoint Test H. VERIFY THE FLOOR OVERRIDE OPERATION Press the override button for FLOOR operation. Is outside air being discharged from the floor duct? GO to F7. GO to Pinpoint Test H. VERIFY THE VENT OVERRIDE OPERATION Press the override button for VENT operation. Is outside air being discharged from the instrument panel GO to F8. registers? GO to Pinpoint Test H.

412-00-29 Climate Control System - General Information 412-00-29 DIAGNOSIS AND TESTING PINPOINT TEST F: THE EATC SYSTEM IS INOPERATIVE, INTERMITTENT OR INCORRECT OPERATION F8 F9 F10 F11 F12 VERIFY THE A/C CLUTCH DOES NOT ENGAGE IN THE VENT MODE Press the override button for VENT operation. Does the A/C clutch engage when the VENT override button REFER to the Powertrain is pressed? Control/Emissions Diagnosis (PC/ED) manual. GO to F9. VERIFY THE MAX A/C OVERRIDE OPERATION Make sure the ambient air temperature is above 5 C (41 F). Press the override button for MAX A/C operation. GO to F10. Is recirculated air being discharged from the instrument panel registers? GO to Pinpoint Test H. VERIFY A/C CLUTCH ENGAGEMENT IN THE MAX A/C MODE Press the override button for MAX A/C operation. Does the A/C clutch engage when the MAX A/C override The test is complete. The system is button is pressed? functioning normally. GO to Pinpoint Test J. CHECK THE EATC MODULE FUNCTIONS Press each function button and observe the display. Does the EATC perform and display any functions? INSTALL a new EATC module (19980). TEST the system for normal operation. GO to F12. CHECK THE VOLTAGE TO THE EATC Disconnect: EATC Module C228b. Key in ON position. Measure the voltage between ground and: EATC module C228b pin 2, circuit 729 (RD/WH) EATC module C228b pin 16, circuit 296 (WH/VT) F13 GO to F13. REPAIR the affected circuit. TEST the Are the voltages greater than 10 volts? system for normal operation. CHECK THE GROUND CIRCUIT TO THE EATC

412-00-30 Climate Control System - General Information 412-00-30 DIAGNOSIS AND TESTING PINPOINT TEST F: THE EATC SYSTEM IS INOPERATIVE, INTERMITTENT OR INCORRECT OPERATION F13 CHECK THE GROUND CIRCUIT TO THE EATC Measure the resistance between the EATC module C228b pin 3, circuit 57 (BK) and ground. G1 G2 INSTALL a new EATC module (19980). TEST the system for normal operation. REPAIR circuit 57 (BK) for an open. TEST Is the resistance less than 5 ohms? the system for normal operation. PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE AIRFLOW IN EACH SETTING Key in ON position. With the engine running, set the blower motor speed to maximum. Check the airflow in each function selector switch setting at engine idle and under acceleration. GO to G2. Is the airflow from only the defroster outlets in each function selector switch setting? GO to G10. CHECK FOR VACUUM AT THE CHECK VALVE Disconnect the vacuum check valve vacuum source line and check for manifold vacuum and connect the vacuum pump. G3 GO to G3. REPAIR or INSTALL a new check valve Is manifold vacuum present at the check valve vacuum vacuum source line. TEST the system for source line? normal operation. CHECK THE VACUUM CHECK VALVE FOR BLOCKAGE Reconnect the vacuum source line to the vacuum check valve.

412-00-31 Climate Control System - General Information 412-00-31 DIAGNOSIS AND TESTING G3 PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE VACUUM CHECK VALVE FOR BLOCKAGE Disconnect the vacuum reservoir line and the function selector switch vacuum line from the vacuum check valve and plug one port. G4 G5 GO to G4. Check for manifold vacuum at the open port on the vacuum check valve. INSTALL a new vacuum check valve Is manifold vacuum present at the open port on the vacuum (19A563). TEST the system for normal check valve? operation. CHECK THE VACUUM CHECK VALVE Connect the vacuum pump to the open port on the vacuum GO to G5. check valve and attempt to pull a vacuum. Can a vacuum be pulled on the vacuum check valve? INSTALL a new vacuum check valve (19A563). TEST the system for normal operation. CHECK THE VACUUM RESERVOIR LINE FOR BLOCKAGE Disconnect the vacuum reservoir line at the vacuum reservoir. Connect the vacuum pump to the vacuum reservoir line at the vacuum check valve connection and attempt to pull a vacuum. G6 REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation. Can a vacuum be pulled on the vacuum reservoir line? GO to G6. CHECK THE VACUUM RESERVOIR LINE FOR LEAKS Plug the vacuum reservoir line at the vacuum reservoir connection.

412-00-32 Climate Control System - General Information 412-00-32 DIAGNOSIS AND TESTING G6 PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE VACUUM RESERVOIR LINE FOR LEAKS Leak test the vacuum reservoir line using the vacuum pump. G7 REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation. Does the vacuum reservoir line leak? GO to G7. CHECK THE VACUUM RESERVOIR FOR A LEAK Connect the vacuum pump reservoir line to the vacuum reservoir. With the vacuum pump connected to the vacuum reservoir line, leak test the vacuum reservoir. INSTALL a new vacuum reservoir (19A566). TEST the system for normal operation. Does the vacuum reservoir leak? GO to G8. G8 CHECK THE FUNCTION SELECTOR SWITCH VACUUM SOURCE LINE FOR BLOCKAGE Disconnect the function selector switch vacuum connector.

412-00-33 Climate Control System - General Information 412-00-33 DIAGNOSIS AND TESTING PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL G8 CHECK THE FUNCTION SELECTOR SWITCH VACUUM SOURCE LINE FOR BLOCKAGE Connect the vacuum pump to the function selector switch vacuum source line and attempt to pull a vacuum. G9 REPAIR or INSTALL a new function selector switch vacuum source line. TEST the system for normal operation. Can a vacuum be pulled on the function selector switch vacuum source line? GO to G9. CHECK THE FUNCTION SELECTOR SWITCH VACUUM SOURCE LINE FOR LEAKS Plug the function selector switch vacuum source line at the vacuum check valve connection. Leak test the function selector switch vacuum source line using the vacuum pump. G10 REPAIR or INSTALL a new function selector switch vacuum source line. TEST the system for normal operation. INSTALL a new function selector switch (19B888). REFER to Section 412-04. Does the function selector switch vacuum source line leak? TEST the system for normal operation. CHECK THE FUNCTION SELECTOR SWITCH FOR BLOCKAGE Disconnect: Function Selector Switch Vacuum Harness.

412-00-34 Climate Control System - General Information 412-00-34 DIAGNOSIS AND TESTING G10 PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE FUNCTION SELECTOR SWITCH FOR BLOCKAGE Connect a vacuum pump to the function selector switch vacuum supply port and try to pull a vacuum in each function selector switch position. If the vacuum pump can pull and hold a vacuum, the switch is plugged. If the vacuum pump pulls a vacuum that slowly decays, the hose is restricted. G11 INSTALL a new function selector switch (19B888). REFER to Section 412-04. TEST the system for normal operation. Is the switch plugged or restricted? GO to G11. LEAK TEST THE FUNCTION SELECTOR SWITCH Connect a vacuum pump to the function selector switch vacuum supply port and plug each control port. G12 INSTALL a new function selector switch At each function selector switch position apply 51 kpa (15 in-hg) (19B888). REFER to Section 412-04. of vacuum. TEST the system for normal operation. Does the vacuum drop exceed 3.37 kpa (1 in-hg) per minute? GO to G12. CHECK THE VACUUM HOSE Disconnect the suspect hose.

412-00-35 Climate Control System - General Information 412-00-35 DIAGNOSIS AND TESTING G12 PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE VACUUM HOSE Connect a vacuum pump to each hose and attempt to pull and hold a vacuum. G13 GO to G13. Does the vacuum in any hose drop exceed 3.37 kpa (1 in-hg) per minute? GO to G14. CHECK THE VACUUM CONTROL MOTOR Disconnect: Vacuum Control Motor. Connect a vacuum pump to the affected vacuum control motor. Apply 51 kpa (15 in-hg) of vacuum. G14 INSTALL a new vacuum control motor (18A318). REFER to Section 412-04. TEST the system for normal operation. REPAIR or INSTALL a new vacuum Does the vacuum drop exceed 1.68 kpa (0.5 in-hg) per harness (19C827). TEST the system for minute? normal operation. CHECK THE VACUUM CONTROL MOTOR HOSES FOR BLOCKAGE Disconnect: Vacuum Control Motors.

412-00-36 Climate Control System - General Information 412-00-36 DIAGNOSIS AND TESTING G14 PINPOINT TEST G: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET MANUAL CLIMATE CONTROL CHECK THE VACUUM CONTROL MOTOR HOSES FOR BLOCKAGE Connect a vacuum pump to each hose and try to pull a vacuum. If the vacuum pump can pull and hold a vacuum, the hose is plugged. If the vacuum pump pulls a vacuum that slowly decays, the hose is restricted. G15 REPAIR or INSTALL a new vacuum harness (19C827). TEST the system for normal operation. Is the hose plugged or restricted? GO to G15. CHECK THE VACUUM CONTROL MOTOR INSTALLATION Check the attachment of the vacuum control motor arm to the damper door. REPAIR the damper door. TEST the system for normal operation. CONNECT the vacuum control motor arm Is the vacuum control motor arm attached to the door or to the door crank arm. TEST the system door crank arm? for normal operation. H1 PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET EATC CHECK THE AIRFLOW IN EACH SETTING Key in ON position. With the engine running, check the airflow in each manual The system is operating normally. override setting on the EATC module during engine idle and under acceleration. If the airflow is from the defrost outlet only Is the airflow correct in each manual override setting? in all settings, GO to H2. If the airflow is incorrect in one setting only, NOTE the non-functional setting. GO to H10. If the airflow is incorrect in MAX only, GO to H14.

412-00-37 Climate Control System - General Information 412-00-37 DIAGNOSIS AND TESTING H2 PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET EATC CHECK FOR VACUUM AT THE CHECK VALVE Disconnect the vacuum check valve vacuum source line and check for manifold vacuum and connect the vacuum pump. H3 GO to H3. REPAIR or INSTALL a new check valve Is manifold vacuum present at the check valve vacuum vacuum source line. TEST the system for source line? normal operation. CHECK THE VACUUM CHECK VALVE FOR BLOCKAGE Reconnect the vacuum source line to the vacuum check valve. Disconnect the vacuum reservoir line and the EATC module vacuum line from the vacuum check valve and plug one port. H4 H5 Check for manifold vacuum at the open port on the vacuum GO to H4. check valve. Is manifold vacuum present at the open port on the vacuum INSTALL a new vacuum check valve. check valve? TEST the system for normal operation. CHECK THE VACUUM CHECK VALVE Connect the vacuum pump to the open port on the vacuum GO to H5. check valve and attempt to pull a vacuum. Can a vacuum be pulled on the vacuum check valve? INSTALL a new vacuum check valve. TEST the system for normal operation. CHECK THE VACUUM RESERVOIR LINE FOR BLOCKAGE Disconnect the vacuum reservoir line at the vacuum reservoir.

412-00-38 Climate Control System - General Information 412-00-38 DIAGNOSIS AND TESTING H5 PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET EATC CHECK THE VACUUM RESERVOIR LINE FOR BLOCKAGE Connect the vacuum pump to the vacuum reservoir line at the vacuum check valve connection and attempt to pull a vacuum. H6 REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation. Can a vacuum be pulled on the vacuum reservoir line? GO to H6. CHECK THE VACUUM RESERVOIR LINE FOR LEAKS Plug the vacuum reservoir line at the vacuum reservoir connection. Leak test the vacuum reservoir line using the vacuum pump. H7 REPAIR or INSTALL a new vacuum reservoir line. TEST the system for normal operation. Does the vacuum reservoir line leak? GO to H7. CHECK THE VACUUM RESERVOIR FOR A LEAK Connect the vacuum pump reservoir line to the vacuum reservoir. With the vacuum pump connected to the vacuum reservoir line, leak test the vacuum reservoir. INSTALL a new vacuum reservoir. TEST the system for normal operation. Does the vacuum reservoir leak? GO to H8.

412-00-39 Climate Control System - General Information 412-00-39 DIAGNOSIS AND TESTING PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET EATC H8 CHECK THE EATC MODULE VACUUM SOURCE LINE FOR BLOCKAGE Disconnect the EATC module vacuum connector. Connect the vacuum pump to the EATC module vacuum source line and attempt to pull a vacuum. H9 REPAIR or INSTALL a new EATC module vacuum source line. TEST the system for normal operation. Can a vacuum be pulled on the EATC module vacuum source line? GO to H9. CHECK THE EATC MODULE VACUUM SOURCE LINE FOR LEAKS Plug the EATC module vacuum source line at the vacuum check valve connection. Leak test the EATC module vacuum source line using the vacuum pump. REPAIR or INSTALL a new EATC module vacuum source line. TEST the system for normal operation. INSTALL a new EATC module (19980). Does the EATC module vacuum source line leak? TEST the system for normal operation.

412-00-40 Climate Control System - General Information 412-00-40 DIAGNOSIS AND TESTING H10 PINPOINT TEST H: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET EATC CHECK THE VACUUM CONTROL MOTOR LINE FOR BLOCKAGE Disconnect the EATC module vacuum connector. Disconnect the vacuum line from the appropriate vacuum control motor noted in step G1. Connect the vacuum pump to the appropriate vacuum control motor line noted in step G1, and attempt to pull a vacuum. H11 REPAIR or INSTALL a new plenum vacuum harness (19C827). TEST the system for normal operation. Can a vacuum be pulled on the vacuum control motor line? GO to H11. CHECK THE VACUUM CONTROL MOTOR LINE FOR LEAKS Plug the vacuum control motor line at the vacuum control motor connection. Leak test the vacuum control motor line using the vacuum pump. REPAIR or INSTALL a new vacuum harness. TEST the system for normal operation. Does the vacuum control motor line leak? GO to H12.