1998 F-150/250 Workshop Manual

Transcription

1 Page 1 of 74 SECTION A: Transfer Case General Information DIAGNOSIS AND TESTING Procedure revision date: 12/04/2002 Transfer Case ESOF Refer to Wiring Diagrams Cell 34, Electric Shift Control for schematic and connector information. Refer to Wiring Diagrams Cell 20, Starting System for schematic and connector information. Refer to Wiring Diagrams Cell 59, Generic Electronic Module for schematic and connector information. Special Tool(s) 73 Digital Multimeter or equivalent 105-R0051 New Generation STAR (NGS) Tester or equivalent 418-F048 ( ) Vacuum Pump or equivalent 416-D001 (D83L-7059-A) Electrical Shift on the Fly (ESOF) Vacuum Schematic 4WD Tables Table 1 4WD Mode Switch Input Resistances

2 Page 2 of 74 Mode Switch Position Resistance (Ohms) 2-Wheel Drive WD HIGH WD LOW Table 2 Transfer Case Shift Relays Outputs HI-to-LO LO-to-HI Mode GROUND BATTERY 4 HIGH to 4 LOW BATTERY GROUND 4 LOW to 4 HIGH GROUND GROUND Brake Motor Table 3 Neutral Safety Switch Input Conditions Transmission State Start/Clutch Depressed Input Neutral Safety Switch Input In Gear Open Open Park Ground Open Neutral Ground Ground (Start) Park Battery Voltage Open (Start) Neutral Battery Voltage Ground Table 4 Contact Plate Sensor Position Codes Contact Plate Code Left Mech.Stop Left Stop 2H 2H E * 4H *E 4H 4L *E 4L Right Mech.Stop A Closed Closed Closed Closed Closed Open Open Open Closed B Open Open Open Closed Closed Closed Closed Closed Closed C Open Closed Closed Closed Closed Closed Closed Open Open D Open Open Closed Closed Open Open Closed Closed Closed * Refers to the code at the point of transition between two positions or areas of the sensor. Inspection and Verification Electronic Shift on the Fly (ESOF 1. Verify the customer concern by operating the 2WD/4WD engagement. 2. Visually inspect for the following obvious signs of mechanical and electrical damage. Visual Inspection Chart Mechanical Switch(es) Electrical Fuse(s) Damaged wiring harness Loose or corroded connector(s) Circuitry 3. If the concern remains after the inspection, connect the New Generation STAR (NGS) Tester to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the NGS menu. If the NGS does not communicate with the vehicle: check that the program card is properly installed. check the connections to the vehicle. check the ignition switch position. 4. If the NGS still does not communicate with the vehicle, refer to the New Generation STAR Tester manual. 5. Perform the DATA LINK DIAGNOSTIC TEST. If the NGS responds with: CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section NO RESP/NOT EQUIP for GEM, go to Pinpoint Test F. SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and perform self-test diagnostics for the GEM. 6. If the DTCs retrieved are related to the concern, go to the GEM Diagnostic Trouble Code (DTC) Index to continue diagnostics. 7. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics. GEM Diagnostic Trouble Code (DTC) Index

3 Page 3 of 74 GEM Diagnostic Trouble Code (DTC) Index DTC Description B1302 Accessory Delay Relay Coil Open or Short to Ground (Only Set if Battery Saver Relay Has Faults) DTC Caused By GEM REFER to Section B1304 Accessory Delay Relay Coil Short to Power GEM REFER to Section B1313 Battery Saver Relay Coil Open or Short to Ground GEM REFER to Section B1315 Battery Saver Relay Coil Short to Power GEM REFER to Section B1317 Battery Voltage HIGH, Greater Than 18.0 Volts GEM REFER to Section B1318 Battery Voltage LOW, Less Than 10 Volts GEM REFER to Section B1322 LF Door Open Warning Circuit Short to Ground, or Door Open GEM REFER to Section Action B1323 Door Open Warning Lamp Open or Short to Ground GEM REFER to Section A or Section B. B1325 Door Open Warning Lamp Short to Power GEM REFER to Section A or Section B B1330 RF Door Open Warning Circuit Short to Ground, or Door Open GEM REFER to Section B1342 ECU is Defective, RAM/ROM Checksum Failure GEM CLEAR the DTCs. RETRIEVE the DTCs. If DTC B1342 is retrieved, REPLACE the GEM. REFER to Section TEST the system for normal operation. B1352 Key-in-Ignition Circuit Open GEM REFER to Section B1355 Ignition RUN Circuit Open GEM REFER to Section , Symptom Chart. B1359 Ignition RUN/ACC Circuit Open GEM REFER to Section , Symptom Chart. B1365 Ignition START Circuit Short to Power GEM REFER to Section , Symptom Chart. B1371 Interior Lamp Relay Coil Open or Short to Ground GEM REFER to Section B1373 Interior Lamp Relay Coil Short to Power GEM REFER to Section B1398 LF One-Touch Down Power Window Relay Coil Open or Short to Ground B1400 LF One-Touch Down Power Window Relay Coil Short to Power GEM REFER to Section GEM REFER to Section B1405 LF Power Window Switch Down Circuit Short to Power GEM REFER to Section B1408 LF Power Window Switch Up Circuit Short to Power GEM REFER to Section B1410 LF Power Window Motor Excessive Current Draw GEM REFER to Section B1426 Safety Belt Lamp Circuit Short to Power GEM REFER to Section A or Section B. B1428 Safety Belt Lamp Circuit Open or Short to Ground GEM REFER to Section A or Section B. B1431 Wiper RUN/PARK Relay Coil Circuit Open or Short to Ground GEM REFER to Section B1432 Wiper RUN/PARK Relay Coil Circuit Short to Power GEM REFER to Section B1434 Wiper HI/LO Speed Relay Coil Circuit Open or Short to Ground GEM REFER to Section B1436 Wiper HI/LO Speed Relay Coil Circuit Short to Power GEM REFER to Section B1438 Wiper Mode Select Switch Open or Short to Power GEM REFER to Section B1441 Wiper Mode Select Switch Circuit Short to Ground GEM REFER to Section B1446 Wiper Motor PARK Sense Circuit Short to Ground GEM REFER to Section B1450 Wiper Interval Delay Switch Circuit Open or Short to Power GEM REFER to Section B1453 Wiper Interval Delay Switch Circuit Short to Ground GEM REFER to Section B1458 Washer Pump Motor Relay Coil Circuit Open or Short to Ground GEM REFER to Section B1460 Washer Pump Motor Relay Coil Short to Power GEM REFER to Section B1462 Safety Belt Switch Circuit Open GEM REFER to Section B1466 Wiper HI/LO Speed t Switching GEM REFER to Section B1467 Wiper HI/LO Speed Motor Circuit Short to Power GEM REFER to Section B1473 Wiper LO Speed Motor Circuit Failure (Wiper Energized and Park Sense t Seen) B1476 Wiper LO Speed Motor Circuit Failure (Wiper Energized and Park Sense t Seen) B1483 Brake Pedal Input Open Circuit ( Brake Input Seen For 8 Ignition Cycles) GEM REFER to Section GEM REFER to Section GEM GO to Pinpoint Test B. B1485 Brake Pedal Input Circuit Short to Battery GEM GO to Pinpoint Test B. B1577 Headlamp/Parking Lamp Input Circuit Short to Power GEM REFER to Section B1610 Illuminated Entry Input Short to Ground GEM REFER to Section B1840 Wiper Power Circuit Failure GEM REFER to Section P0500 Vehicle Speed Signal t Detected GEM GO to Pinpoint Test B. P Wheel Drive HI Indicator Open or Short to Ground GEM GO to Pinpoint Test C. P Wheel Drive HI Indicator Short to Power GEM GO to Pinpoint Test C. P Wheel Drive LO Indicator Open or Short to Ground GEM GO to Pinpoint Test C.

4 Page 4 of 74 P Wheel Drive LO Indicator Short to Power GEM GO to Pinpoint Test C. P Wheel Drive Mode Select Switch Open or Short to Power GEM GO to Symptom Chart. P Wheel Drive Mode Select Switch Circuit Short to Ground GEM GO to Symptom Chart. P1819 Neutral Safety Switch Input Short to Ground GEM GO to Pinpoint Test B. P1820 Transfer Case LO to HI Shift Relay Coil Open or Short to Ground GEM GO to Pinpoint Test A. P1822 Transfer Case LO to HI Shift Relay Coil Short to Power GEM GO to Pinpoint Test A. P Wheel Drive Electric Clutch Relay Open or Short to Ground GEM GO to Pinpoint Test E. P Wheel Drive Electric Clutch Relay Short to Power GEM GO to Pinpoint Test E. P1828 Transfer Case HI to LO Shift Relay Open or Short to Ground GEM GO to Pinpoint Test A. P1830 Transfer Case HI to LO Shift Relay Short to Power GEM GO to Pinpoint Test A. P1832 Front Axle 4-Wheel Drive Solenoid Open or Short to Ground GEM GO to Pinpoint Test C. P1834 Front Axle 4-Wheel Drive Solenoid Short to Power GEM GO to Pinpoint Test C. P1838 Transfer Case Shift Motor Fails to Move (Energized Relays, Motor Does t Move) GEM REFER to Section A. P1846 Transfer Case Contact Plate A Open Circuit GEM GO to Symptom Chart. P1850 Transfer Case Contact Plate B Open Circuit GEM GO to Symptom Chart. P1854 Transfer Case Contact Plate C Open Circuit GEM GO to Symptom Chart. P1858 Transfer Case Contact Plate D Open Circuit GEM GO to Symptom Chart. P1866 Transfer Case System Concern, Contact Plate Failure GEM GO to Symptom Chart. P1867 Transfer Case Contact Plate Open or Short to Ground GEM GO to Symptom Chart. P1876 Transfer Case 2-Wheel Drive Solenoid Open or Short to Ground GEM GO to Pinpoint Test C. P1877 Transfer Case 2-Wheel Drive Solenoid Short to Power GEM GO to Pinpoint Test C. P1891 Transfer Case Contact Plate Ground Return Open Circuit GEM GO to Symptom Chart. GEM Parameter Identification (PID) Index GEM Parameter Identification (PID) Index PID Description Expected Values ACCDLY Accessory Delay Relay Coil Circuit ON---, OFF---, ON-B-, OFFO-G AXL_DIS 4WD Center Axle Disconnect ON---, OFF---, ON-B-, OFFO-G AXLSTAT 4WD Center Axle Disconnect ON, OFF BATSAV Battery Saver Relay Circuit ON---, OFF---, ON-B-, OFFO-G BOO_GEM Brake Pedal Position (BPP) Switch Input ACTIVE, notact CLTCHSW Clutch Pedal Position (CPP) Switch ACTIVE, notact D_DN_ Window Regulator Control Down Switch State OFF, DOWN SW D_UP_ Window Regulator Control Up Switch State OFF, UP SW D_PWRLY One Touch Down Relay Coil Circuit Status OFF, ON D_ Window Regulator Electric Drive Motor Current 0.25 amp increments PWAMP D_PWPK Window Regulator Electric Drive Current 0.25 amp increments DRAJAR_L Door Ajar Indicator Circuit ON---, OFF---, ON-B-, OFFO-G D_DR_SW LH Door Open Warning Lamp Switch CLOSED, AJAR D_SBELT LH Safety Belt IN, OUT HALLPWR Hall Effect Speed Sensor Power ON---, OFF---, ON-B-, OFFO-G ILLE_SW Illuminated Entry Input (From RAP Module) ON, OFF IGN_GEM Ignition Switch States START, RUN, OFF, ACCY IGN_KEY Ignition Key-In/Out IN, OUT INTLMP Interior Lamp Relay Circuit ON---, OFF---, ON-B-, ONO-G MTR_CCW HI to LO Shift Relay Coil Status ON---, OFF---, ON-B-, OFFO-G MTR_CW LO to HI Shift Relay Coil Status ON---, OFF---, ON-B-, OFFO-G NTRL_SW Transmission Range Sensor Input NTRL, notntrl OTD_SW One Touch Down Switch State OFF, DOWN P_DR_SW RH Door Open Warning Lamp Switch CLOSED, AJAR

5 Page 5 of 74 PARK_SW Headlamp Control Input Switch ON, OFF PLATE_A Transfer Case Contact Plate Switch A OPEN, CLOSED PLATE_B Transfer Case Contact Plate Switch B OPEN, CLOSED PLATE_C Transfer Case Contact Plate Switch C OPEN, CLOSED PLATE_D Transfer Case Contact Plate Switch D OPEN, CLOSED PLATEPW Contact Plate Ground Output ON, OFF SBLTMP Safety Belt Warning Indicator ON---, OFF---, ON-B-, OFFO-G SPEEDWP Speed Dependent Wiper Function ACTIVE, notact VBATGEM Battery 0.1 Volt DC per count VSS_GEM Vehicle Speed Sensor KPH WASHRLY Washer Pump Relay Circuit ON---, OFF---, ON-B-, OFFO-G WASH_SW Washer Relay Output ON---, OFF---, ON-B-, OFFO-G WPHISP Wiper HI/LO Relay Status ON---, OFF---, ON-B-, OFFO-G WPMODE Wiper/Washer Switch Status WASH, OPEN, INVLD, OFF, INTVL 1-7, LOW, HIGH WPPK_PK Wiper Park to Park Time 0 to 65 ms WPPRKSW Wiper Motor Switch Status PARKED, notprk WPRUN Wiper Run/Park Relay Status ON---, OFF---, ON-B-, OFFO-G 2WDSOL 2WD Solenoid Status ON---, OFF---, ON-B-, OFFO-G 4WDCLST Four Wheel Drive Clutch Relay Control ON---, OFF---, ON-B-, OFFO-G 4WDHIGH 4WD High Indicator Status ON---, OFF---, ON-B-, OFFO-G 4WDLOW 4WD Low Indicator Status ON---, OFF---, ON-B-, OFFO-G 4WDSGEM 4WD Mode INVLD, 2WD, 4WDLOW, 4WDHIGH, OFFO-G 4WDSOL 4WD Solenoid Status ON---, OFF---, ON-B-, OFFO-G GEM Active Command Index GEM Active Command Index Active Command Display Action PID LATCH PID LATCH ON, OFF WINDSHIELD WIPER WIPER RLY ON, OFF WINDSHIELD WIPER SPEED RLY ON, OFF WINDSHIELD WIPER WASH RLY ON, OFF WARNING LAMPS AND CHIME SBLT LAMP ON, OFF WARNING LAMPS AND CHIME CHIME ON, OFF WINDSHIELD WIPER AJAR LAMP ON, OFF BATTERY SAVER BATT SAVR ON, OFF INTERIOR COURTESY LAMPS INT LAMPS ON, OFF ONE TOUCH DOWN AND ACCESSORY DELAY ACCY RLY ON, OFF ONE TOUCH DOWN AND ACCESSORY DELAY ONE TOUCH ON, OFF 4-WHEEL ELECTRONIC SHIFT CW/CCW ON, OFF 4-WHEEL ELECTRONIC SHIFT HIGH LAMP ON, OFF 4-WHEEL ELECTRONIC SHIFT LOW LAMP ON, OFF 4-WHEEL ELECTRONIC SHIFT AXLE ENGG ON, OFF 4-WHEEL ELECTRONIC SHIFT AXLE DSCN ON, OFF 4-WHEEL ELECTRONIC SHIFT PLATE PWR ON, OFF 4-WHEEL ELECTRONIC SHIFT SHFT CLCH ON, OFF Symptom Chart Electronic Shift on the Fly (ESOF) Symptom Chart Condition Possible Sources Action The Vehicle Does t Shift Between 2WD and 4WD Modes Properly The Vehicle Does t Shift Between 4WD High and 4WD Low Modes Properly 4 WD mode switch. Transfer case shift relays. Contact plate A, B, C, or D. Transfer case shift motor. Circuitry. Transfer case mechanism. 4WD mode switch. Neutral safety switch. Brake pedal position (BPP) switch. GO to Pinpoint Test A. GO to Pinpoint Test B.

6 Page 6 of 74 The Front Axle Is t Engaging Properly (Transfer Case Motor Movement OK) The 4x4 HIGH and/or 4x4 LOW Range Indicator Do/Does t Operate Properly The 4x4 HIGH Does t Engage at Speed Properly (Driveline Does t Synchronize Properly) But Does Engage at Rest Communication With the Module GEM Transfer case mechanism. Digital transmission range (TR) sensor. Circuitry. 4x4 solenoid. 4x2 solenoid. Vacuum motor. Circuitry. Vacuum lines. Front differential mechanism. Bulb. Digital (TR). Circuitry. ESOF clutch relay. Transfer case electric clutch. Transfer case clutch armature. Hub release spring. Circuitry. Fuse(s). Circuitry. GEM. Fuse junction panel. GO to Pinpoint Test C. GO to Pinpoint Test D. GO to Pinpoint Test E. GO to Pinpoint Test F. Pinpoint Tests PINPOINT TEST A: THE VEHICLE DOES NOT SHIFT BETWEEN 2WD AND 4WD MODES PROPERLY CONDITIONS A1 CHECK THE VOLTAGE OUTPUT FROM FUSE JUNCTION PANEL FUSE 15 (5A) DETAILS/RESULTS/ACTIONS Measure the voltage between fuse junction panel fuse 15 (10A) pin 1 and ground. Is the voltage greater than 10 volts? GO to A4. GO to A2. A2 CHECK FUSE JUNCTION PANEL FUSE 15 (5A) AND POWER DISTRIBUTION BOX FUSE 22 (50A) Fuse 15 (10A) Fuse 22 (50A) Are the fuses OK? GO to A3.

7 Page 7 of 74 A3 CHECK CIRCUIT 1052 (T/BK) FOR VOLTAGE REPLACE the fuse(s). CLEAR the DTCs. TEST the system for normal operation. If the fuse(s) fail again, CHECK for a short to ground. REPAIR as necessary. Fuse Junction Panel C243 Measure the voltage between fuse junction panel C243-11, circuit 1052 (T/BK), and ground. Is the voltage greater than 10 volts? A4 CHECK THE IGNITION STATES MONITOR THE GEM PID IGN_GEM REPLACE the fuse junction panel. CLEAR the DTCs. TEST the system for normal operation. REPAIR circuit 1052 (T/BK). CLEAR the DTCs. TEST the system for normal operation. NGS NOTE: If the vehicle is equipped with a manual transmission, depress the clutch pedal while turning the ignition switch to the START position. Monitor the GEM PID IGN_GEM and rotate the ignition switch (11572) through the START, RUN, OFF, and ACC positions. Do the PID values agree with the ignition switch positions? A5 RETRIEVE THE DIAGNOSTIC TROUBLE CODES (DTCS) GO to A5. REPAIR the ignition circuit(s) (RUN/ACC: circuit 297 [BK/LG], RUN: circuit 1040 [R/LB], START: circuit 32 [R/LB] or circuit 481 [GY/Y]) in question. CLEAR the DTCs. TEST the system for normal operation. Retrieve and Document Continuous DTCs Clear Continuous DTCs GEM On-Demand Self-Test Are any DTCs recorded?

8 Page 8 of 74 If DTC B1342, REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. If DTC P1804, GO to Pinpoint Test D. If DTC P1806, GO to Pinpoint Test D. If DTC P1808, GO to Pinpoint Test D. If DTC P1810, GO to Pinpoint Test D. If DTC P1812, GO to A8. If DTC P1815, GO to A8. If DTC P1820, GO to A24. If DTC P1822, GO to A24. If DTC P1824, GO to Pinpoint Test E. If DTC P1826, GO to Pinpoint Test E. If DTC P1828, GO to A24. If DTC P1830, GO to A24. If DTC P1832, GO to Pinpoint Test C. If DTC P1834, GO to Pinpoint Test C. If DTC P1846, GO to A41. If DTC P1850, GO to A41. If DTC P1854, GO to A41. If DTC P1858, GO to A41. If DTC P1866, GO to A41. If DTC P1867, GO to A41. If DTC P1891, GO to A41. If DTC P1876, GO to Pinpoint Test C. If DTC P1877, GO to Pinpoint Test C. GO to A6. A6 CHECK THE HIGH LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAND HIGH LAMP ON Trigger the GEM active command HIGH LAMP to ON then OFF. The 4x4 indicator should illuminate and then turn off. Does the indicator illuminate correctly? GO to A7. GO to Pinpoint Test D. A7 CHECK THE LOW LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAND LOW LAMP ON Trigger the GEM active command LOW LAMP to ON then OFF. The LOW indicator should illuminate and then turn off. Does the indicator illuminate correctly? GO to A8. GO to Pinpoint Test D. A8 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM.

9 Page 9 of 74 Monitor the GEM PID 4WDSGEM. Place the mode switch in the 2H position. Does the GEM PID indicate 2WD? GO to A9. GO to A11. A9 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM (4H) Place the mode switch in the 4H position. Does the GEM PID indicate 4WDHGH? GO to A10. GO to A11. A10 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM (4L) Place the mode switch in the 4L position. Does the GEM PID indicate 4WDLOW? GO to A20. A11 CHECK THE 4WD MODE SWITCH 2H GO to A11.

10 Page 10 of 74 Mode Switch C230 Place the mode switch in the 2H position. Measure the resistance between the mode switch terminal 2 and terminal 3. Is the resistance between 3700 and 4100 ohms? GO to A12. A12 CHECK THE 4WD MODE SWITCH 4H REPLACE the mode switch; REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. Place the mode switch in the 4H position. Measure the resistance between the mode switch terminals 2 and 3. Is the resistance between 1050 and 1150 ohms? GO to A13.

11 Page 11 of 74 A13 CHECK THE 4WD MODE SWITCH 4L REPLACE the mode switch; REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. Place the mode switch in the 4L position. Measure the resistance between the mode switch terminals 2 and 3. Is the resistance between 340 and 380 ohms? GO to A14. A14 CHECK CIRCUIT 780 (DB) FOR OPEN REPLACE the mode switch; REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. GEM C241 Measure the resistance between mode switch C230-3, circuit 780 (DB), and GEM C241-8, circuit 780 (DB). Is the resistance less than 5 ohms? GO to A15. A15 CHECK CIRCUIT 780 (DB) FOR SHORT TO GROUND REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between GEM C241-8, circuit 780 (DB), and ground.

12 Page 12 of 74 Is the resistance greater than 10,000 ohms? GO to A16. A16 CHECK CIRCUIT 780 (DB) FOR SHORT TO POWER REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between GEM C241-8, circuit 780 (DB), and ground. Is any voltage indicated? REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. A17 CHECK CIRCUIT 682 (DB) FOR OPEN GO to A17. GEM C239 Measure the resistance between mode switch C230-2, circuit 682 (DB), and GEM C239-21, circuit 682 (DB). Is the resistance less than 5 ohms? GO to A18.

13 Page 13 of 74 A18 CHECK CIRCUIT 682 (DB) FOR SHORT TO GROUND REPLACE circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. Multi-Function Switch C259 Measure the resistance between mode switch C230-2, circuit 682 (DB), and ground. Is the resistance greater than 10,000 ohms? GO to A19. A19 CHECK CIRCUIT 682 (DB) FOR SHORT TO POWER REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between mode switch C230-2, circuit 682 (DB), and ground. Is any voltage indicated? REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. A20 CHECK THE FRONT AXLE ENGAGEMENT REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Trigger the GEM active commands AXLE ENGG to ON and AXLE DSCN to OFF and drive a short distance. Raise and support the vehicle with the engine running; refer to Section Spin one front tire. The other tire should spin in the opposite direction.

14 Page 14 of 74 Is the axle disconnect working properly? EXIT the active command mode; GO to A21. A21 CHECK THE FRONT DRIVESHAFT ENGAGEMENT GO to Pinpoint Test C. Place the mode switch in the 4H position. Verify the front and rear driveshafts both spin. Is the transfer case locking the front driveshaft to the rear driveshaft? GO to A22. A22 CHECK THE FRONT DRIVESHAFT DISENGAGEMENT GO to A24. NOTE: When 4WD is disengaged, the front driveshaft may spin due to viscous drag in the transfer case, especially if cold. If this occurs, the front driveline can easily be stopped. Place the mode switch in the 2H position. Only the rear driveshaft should spin. Does only the rear driveshaft spin? GO to A23. A23 CHECK THE FRONT AXLE DISENGAGEMENT GO to A24. Trigger the GEM active commands AXLE ENGG to OFF and AXLE DSCN to ON. Spin one front tire and the other front tire should not spin. Is the axle disconnect working properly? The 4WD system is working properly. GO to Pinpoint Test C.

15 Page 15 of 74 A24 CHECK THE TRANSFER CASE SHIFT RELAYS COIL ACTIVATION MONITOR THE GEM PIDS MTR_CCW AND MTR_CW Monitor the GEM PIDs MTR_CCW and MTR_CW while triggering the GEM active command CW/CCW ON. Do the GEM PIDs MTR_CCW and MTR_CW indicate ON---? GO to A25. If the GEM PID displays ON-B-, GO to A30. A25 CHECK THE TRANSFER CASE SHIFT RELAYS COIL DE-ACTIVATION MONITOR THE GEM PIDS MTR_CCW AND MTR_CW Monitor the GEM PIDS MTR_CCW and MTR_CW while triggering the GEM active command CW/CCW OFF. Do the GEM PIDs MTR_CCW and MTR_CW indicate OFF---? GO to A33. If the GEM PID displays OFFO-G, GO to A26. A26 CHECK THE VOLTAGE TO THE TRANSFER CASE SHIFT RELAYS COILS CIRCUIT 704 (DG/LG) Transfer Case Shift Relays C221 Measure the voltage between transfer case shift relays connector C221-5, circuit 704 (DG/LG), and ground. Is the voltage greater than 10 volts? GO to A27. A27 CHECK CIRCUIT 781 (O/LB) FOR OPEN REPAIR circuit 704 (DG/LG). CLEAR the DTCs. TEST the system for normal operation. GEM C241 Measure the resistance between transfer case shift relays C221-9, circuit 781 (O/LB), and GEM C241-17, circuit 781 (O/LB).

16 Page 16 of 74 Is the resistance less than 5 ohms? GO to A28. A28 CHECK CIRCUIT 782 (BR/W) FOR OPEN REPAIR circuit 781 (O/LB). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between transfer case shift relays C221-8, circuit 782 (BR/W), and GEM C241-16, circuit 782 (BR/W). Is the resistance less than 5 ohms? GO to A29. A29 CHECK CIRCUITS 781 (O/LB) AND 782 (BR/W) FOR SHORT(S) TO GROUND REPAIR circuit 782 (BR/W). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between transfer case shift relays C221-8, circuit 782 (BR/W), and ground; and between transfer case shift relay C221-9, circuit 781 (O/LB), and ground. Are the resistances greater than 10,000 ohms? A30 CHECK CIRCUIT 782 (BR/W) FOR SHORT TO POWER GO to A32. REPAIR circuit 781 (O/LB) and/or circuit 782 (BR/W). CLEAR the DTCs. TEST the system for normal operation. Transfer Case Shift Relays C221

17 Page 17 of 74 GEM C241 Measure the voltage between transfer case shift relays C221-8, circuit 782 (BR/W), and ground. Is any voltage indicated? REPAIR circuit 782 (BR/W). CLEAR the DTCs. TEST the system for normal operation. A31 CHECK CIRCUIT 781 (O/LB) FOR SHORT TO POWER GO to A31. Measure the voltage between transfer case shift relays connector C221-9, circuit 781 (O/LB), and ground. Is any voltage indicated? REPAIR circuit 781 (O/LB). CLEAR the DTCs. TEST the system for normal operation. A32 CHECK THE TRANSFER CASE SHIFT RELAYS COILS GO to A32. Measure the resistance between the transfer case shift relays terminal 5 and terminals 8, 9. Are the resistances between 60 and 160 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. REPLACE the transfer case shift relays. CLEAR the DTCs. TEST the system for normal operation.

18 Page 18 of 74 A33 CHECK THE VOLTAGE TO THE ELECTRIC SHIFT MOTOR MOTOR ON Transfer Case Assembly C201 Trigger the GEM active command CW/CCW to ON. Measure the voltage between transfer case assembly C201-14, circuit 778 (O), and ground; and between transfer case assembly C201-15, circuit 777 (Y), and ground. Are the voltages greater than 10 volts? GO to A35. GO to A34. A34 CHECK THE VOLTAGE TO THE TRANSFER CASE SHIFT RELAYS SWITCH CIRCUIT 704 (DG/LG) Transfer Case Shift Relays C221 Measure the voltage between transfer case shift relays C221-3, circuit 704 (DG/LG), and ground. Is the voltage greater than 10 volts? GO to A38. A35 CHECK THE VOLTAGE TO THE ELECTRIC SHIFT MOTOR MOTOR OFF REPAIR circuit 704 (DG/LG). CLEAR the DTCs. TEST the system for normal operation.

19 Page 19 of 74 Trigger the GEM active command CW/CCW to OFF. Measure the voltage between transfer case assembly C201-14, circuit 778 (O), and ground; and between transfer case assembly C201-15, circuit 777 (Y), and ground. Are the voltages greater than 10 volts? GO to A36. GO to A37. A36 CHECK CIRCUITS 777 (Y) AND 778 (O) FOR SHORT(S) TO POWER Transfer Case Shift Relays C221 Measure the voltage between transfer case assembly C201-14, circuit 778 (O), and ground; and between transfer case assembly C201-15, circuit 777 (Y), and ground. Is any voltage indicated? REPAIR circuit 778 (O) and/or circuit 777 (Y). CLEAR the DTCs. TEST the system for normal operation. A37 CHECK CIRCUITS 777 (Y) AND 778 (O) REPLACE the transfer case shift relays. CLEAR the DTCs. TEST the system for normal operation. Trigger the GEM active command CW/CCW to OFF. Measure the resistance between transfer case assembly C201-14, circuit 778 (O), and ground; and between transfer case assembly C201-15, circuit 777 (Y), and ground.

20 Page 20 of 74 Are the resistances less than 5 ohms? RECONNECT the transfer case assembly. GO to A41. A38 CHECK CIRCUIT 777 (Y) FOR OPEN GO to A40. Measure the resistance between transfer case shift relays C221-7, circuit 777 (Y), and transfer case assembly C201-15, circuit 777 (Y). Is the resistance less than 5 ohms? GO to A39. A39 CHECK CIRCUIT 778 (O) FOR OPEN REPAIR circuit 777 (Y). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between transfer case shift relays C221-10, circuit 778 (O), and transfer case assembly C201-14, circuit 778 (O). Is the resistance less than 5 ohms? A40 CHECK THE GROUND TO THE TRANSFER CASE SHIFT RELAYS CIRCUIT 57 (BK) REPLACE the transfer case shift relays. CLEAR the DTCs. TEST the system for normal operation. REPAIR circuit 778 (O). CLEAR the DTCs. TEST the system for normal operation. Transfer Case Shift Relays C221

21 Page 21 of 74 Measure the resistance between transfer case shift relays C221-1, circuit 57 (BK), and ground. Is the resistance less than 5 ohms? REPLACE the transfer case shift relays. CLEAR the DTCs. TEST the system for normal operation. A41 CHECK THE CONTACT PLATE SWITCHES REPAIR circuit 57 (BK). CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PIDs PLATE_A, PLATE_B, PLATE_C, and PLATE_D. Place the mode switch in 2H and record the GEM PIDs. Depress the brake pedal. Place the mode switch in 4H and record the GEM PIDs. Compare the PIDs with Table 4 Contact Plate Sensor Position Codes; refer to 4WD Tables. Do the GEM PIDs agree with Table 4?

22 Page 22 of 74 REPAIR the transfer case (7A195) or shift motor assembly; REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. A42 MONITOR THE GEM PID PLATE_A FOR OPEN GO to A42. Transfer Case Assembly C201 Trigger the GEM active command PLATE POWER to ON. Monitor the GEM PID PLATE_A. Does the GEM PID PLATE_A not indicate OPEN? GO to A44. GO to A43. A43 CHECK THE CIRCUIT 771 (P/Y) TO THE CONTACT PLATE SWITCH A MONITOR THE GEM PID PLATE_A Connect a jumper wire between transfer case assembly C201-10, circuit 762 (Y/W), and C201-5, circuit 771 (P/Y). Monitor the GEM PID PLATE_A. Does the GEM PID PLATE_A indicate CLOSED? REMOVE the jumper wire; GO to A49. A44 CHECK CIRCUIT 771 (P/Y) FOR SHORT TO GROUND GO to A45.

23 Page 23 of 74 GEM C241 Measure the resistance between transfer case assembly C201-5, circuit 771 (P/Y), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. A45 CHECK CIRCUIT 771 (P/Y) FOR OPEN REPAIR circuit 771 (P/Y). CLEAR the DTCs. CYCLE the ignition OFF and then to RUN. TEST the system for normal operation. Measure the resistance between transfer case assembly C201-5, circuit 771 (P/Y), and GEM C Is the resistance less than 5 ohms? GO to A46. A46 CHECK CIRCUIT 771 (P/Y) FOR SHORT TO POWER REPAIR circuit 771 (P/Y). CLEAR the DTCs. TEST the system for normal operation. GEM C241 Measure the voltage between transfer case assembly C201-5, circuit 771 (P/Y), and ground.

24 Page 24 of 74 Is any voltage indicated? REPAIR circuit 771 (P/Y). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. A47 CHECK CIRCUIT 762 (Y/W) FOR SHORT TO POWER GO to A47. Measure the voltage between GEM C241-12, circuit 762 (Y/W), and ground. Is any voltage indicated? REPAIR circuit 762 (Y/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. A48 CHECK CIRCUIT 762 (Y/W) FOR OPEN GO to A48. Measure the resistance between transfer case assembly C201-10, and GEM C241-12, circuit 762 (Y/W). Is the resistance less than 5 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. A49 MONITOR THE GEM PID PLATE_B FOR OPEN REPAIR circuit 762 (Y/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Monitor the GEM PID PLATE_B. Does the GEM PID PLATE_B not indicate OPEN?

25 Page 25 of 74 GO to A51. GO to A50. A50 CHECK THE CIRCUIT 770 (W) TO THE CONTACT PLATE SWITCH B MONITOR THE GEM PID PLATE_B Connect a jumper wire between transfer case assembly C201-10, circuit 762 (Y/W), and C201-1, circuit 770 (W). Monitor the GEM PID PLATE_B. Does the GEM PID PLATE_B indicate CLOSED? REMOVE the jumper wire; GO to A54. A51 CHECK CIRCUIT 770 (W) FOR SHORT TO GROUND GO to A52. GEM C241 Measure the resistance between transfer case assembly C201-1, circuit 770 (W), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. A52 CHECK CIRCUIT 770 (W) FOR OPEN REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Measure the resistance between transfer case assembly C201-1, circuit 770 (W), and GEM C241-20, circuit 770 (W).

26 Page 26 of 74 Is the resistance less than 5 ohms? GO to A53. A53 CHECK CIRCUIT 770 (W) FOR SHORT TO POWER REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Measure the voltage between transfer case assembly C201-1, circuit 770 (W), and ground. Is any voltage indicated? REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. A54 MONITOR THE GEM PID PLATE_C FOR OPEN REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID PLATE_C. Does the GEM PID PLATE_C not indicate OPEN? GO to A56. GO to A55. A55 CHECK THE CIRCUIT 764 (BR/W) TO THE CONTACT PLATE SWITCH C MONITOR THE GEM PID PLATE_C Connect a jumper wire between transfer case assembly C207-9, circuit 764 (BR/W), and C201-10, circuit 762 (Y/W).

27 Page 27 of 74 Monitor the GEM PID PLATE_C. Does the GEM PID PLATE_C indicate CLOSED? A56 CHECK CIRCUIT 764 (BR/W) FOR SHORT TO GROUND REMOVE the jumper wire; GO to A59. GO to A57. GEM C241 Measure the resistance between transfer case assembly C201-9, circuit 764 (BR/W), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. A57 CHECK CIRCUIT 764 (BR/W) FOR OPEN REPAIR circuit 764 (BR/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Measure the resistance between transfer case assembly C201-9, circuit 764 (BR/W), and GEM C241-19, circuit 764 (BR/W). Is the resistance less than 5 ohms?

28 Page 28 of 74 A58 CHECK CIRCUIT 764 (BR/W) FOR SHORT TO POWER GO to A58. REPAIR circuit 764 (BR/W). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between transfer case assembly C201-9, circuit 764 (BR/W), and ground. Is any voltage indicated? REPAIR circuit 764 (BR/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. A59 MONITOR THE GEM PID PLATE_D FOR OPEN REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID PLATE_D. Does the GEM PID PLATE_D not indicate OPEN? GO to A61. GO to A60. A60 CHECK CIRCUIT 763 (O/W) TO THE CONTACT PLATE SWITCH D MONITOR THE GEM PID PLATE_D Connect a jumper wire between transfer case assembly C201-10, circuit 762 (Y/W), and C201-13, circuit 763 (O/W). Monitor the GEM PID PLATE_D. Does the PID PLATE_D indicate closed? A61 CHECK CIRCUIT 763 (O/W) FOR SHORT TO GROUND REPLACE the transfer case shift motor (7G360); REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. GO to A62.

29 Page 29 of 74 GEM C241 Measure the resistance between transfer case assembly C201-13, circuit 763 (O/W), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. A62 CHECK CIRCUIT 763 (O/W) FOR OPEN REPAIR circuit 763 (O/W). CLEAR the DTCs. CYCLE the ignition OFF and then to RUN. TEST the system for normal operation. Measure the resistance between transfer case assembly C201-13, circuit 763 (O/W), and GEM C241-18, circuit 763 (O/W). Is the resistance less than 5 ohms? GO to A63. A63 CHECK CIRCUIT 763 (O/W) FOR SHORT TO POWER REPAIR circuit 763 (O/W). CLEAR the DTCs. CYCLE the ignition OFF and then to RUN. TEST the system for normal operation. Measure the voltage between transfer case assembly C201-13, circuit 763 (O/W), and ground. Is any voltage indicated?

30 Page 30 of 74 REPAIR circuit 763 (O/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. PINPOINT TEST B: THE VEHICLE DOES NOT SHIFT BETWEEN 4WD HIGH AND 4WD LOW MODES PROPERLY CONDITIONS B1 CHECK THE VOLTAGE OUTPUT FROM FUSE JUNCTION PANEL FUSE 15 (5A) DETAILS/RESULTS/ACTIONS Measure the voltage between fuse 15 (5A) pin 1 and ground. Is the voltage greater than 10 volts? GO to B4. GO to B2. B2 CHECK FUSE JUNCTION PANEL FUSE 15 (5A) AND POWER DISTRIBUTION BOX FUSE 22 (50A) Fuse 15 (5A) Fuse 22 (50A) Are the fuses OK? GO to B3. B3 CHECK CIRCUIT 1052 (T/BK) FOR VOLTAGE REPLACE the fuse(s). CLEAR the DTCs. TEST the system for normal operation. If the fuse(s) fail again, CHECK for a short to ground. REPAIR as necessary. Fuse Junction Panel C243 Measure the voltage between fuse junction panel C243-11, circuit 1052 (T/BK), and ground.

31 Page 31 of 74 Is the voltage greater than 10 volts? B4 CHECK THE IGNITION STATES MONITOR THE GEM PID IGN_GEM REPLACE the fuse junction panel. CLEAR the DTCs. TEST the system for normal operation. REPAIR circuit 1052 (T/BK). CLEAR the DTCs. TEST the system for normal operation. NGS NOTE: If the vehicle is equipped with a manual transmission, depress the clutch pedal while turning the ignition switch to START. Monitor the GEM PID IGN_GEM and rotate the ignition switch through the START, RUN, OFF, and ACC positions. Do the PID values agree with the ignition switch positions? B5 RETRIEVE THE DIAGNOSTIC TROUBLE CODES (DTCS) GO to B5. REPAIR the ignition circuit(s) (RUN/ACC: circuit 297 [BK/LB], RUN: circuit 1040 [R/LB], START: circuit 32 [R/LB] or circuit 481 [GY/Y]) in question. CLEAR the DTCs. TEST the system for normal operation. Retrieve and Document Continuous DTCs Clear Continuous DTCs GEM On-Demand Self-Test Are any DTCs recorded? If DTC B1342, REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. If DTC P0500, GO to B27. If DTC P1483, GO to B20. If DTC P1485, GO to B20. If DTC P1804, GO to Pinpoint Test D. If DTC P1806, GO to Pinpoint Test D. If DTC P1808, GO to Pinpoint Test D. If DTC P1810, GO to Pinpoint Test D.

32 Page 32 of 74 If DTC P1812, GO to B8. If DTC P1815, GO to B8. If DTC P1819, GO to B24. If DTC P1820, GO to Pinpoint Test A. If DTC P1822, GO to Pinpoint Test A. If DTC P1824, GO to Pinpoint Test E. If DTC P1826, GO to Pinpoint Test E. If DTC P1828, GO to Pinpoint Test A. If DTC P1830, GO to Pinpoint Test A. If DTC P1832, GO to Pinpoint Test C. If DTC P1834, GO to Pinpoint Test C. If DTC P1846, GO to B31. If DTC P1850, GO to B31. If DTC P1854, GO to B31. If DTC P1858, GO to B31. If DTC P1866, GO to Pinpoint Test A. If DTC P1867, GO to Pinpoint Test A. If DTC P1876, GO to Pinpoint Test C. If DTC P1877, GO to Pinpoint Test C. If DTC P1891, GO to B31. GO to B6. B6 CHECK THE HIGH LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAND HIGH LAMP ON Trigger the GEM active command HIGH LAMP to ON, then OFF. The 4x4 indicator should illuminate, then turn off. Does the indicator illuminate correctly? GO to B7. GO to Pinpoint Test D. B7 CHECK THE LOW LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAND LOW LAMP ON Trigger the GEM active command LOW LAMP to ON, then OFF. The LOW indicator should illuminate, then turn off. Does the indicator illuminate correctly? GO to B8. GO to Pinpoint Test D. B8 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM Monitor the GEM PID 4WDSGEM. Place the mode switch in the 2H position.

33 Page 33 of 74 Does the GEM PID indicate 2WD? GO to B9. GO to B11. B9 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM (4H) Place the mode switch in the 4H position. Does the GEM PID indicate 4WDHGH? GO to B10. GO to B11. B10 CHECK THE 4WD MODE SELECT SWITCH MONITOR THE GEM PID 4WDSGEM (4L) Place the mode switch in the 4L position. Does the GEM PID indicate 4WDLOW? GO to B20. B11 CHECK THE 4WD MODE SWITCH 2H GO to B11. Mode Switch C230 Place the mode switch in the 2H position.

34 Page 34 of 74 Measure the resistance between mode switch terminals 2 and 3. Is the resistance between 3700 and 4100 ohms? GO to B12. B12 CHECK THE 4WD MODE SWITCH 4H REPLACE the mode switch. REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. Place the mode switch in the 4H position. Measure the resistance between the mode switch terminals 2 and 3. Is the resistance between 1050 and 1150 ohms? GO to B13. B13 CHECK THE 4WD MODE SELECT SWITCH 4L REPLACE the mode switch. REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. Place the mode switch in the 4L position.

35 Page 35 of 74 Measure the resistance between the mode switch terminals 2 and 3. Is the resistance between 340 and 380 ohms? GO to B14. B14 CHECK CIRCUIT 780 (DB) FOR OPEN REPLACE the mode switch. REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. GEM C241 Measure the resistance between mode switch C230-3, circuit 780 (DB), and GEM C241-8, circuit 780 (DB). Is the resistance less than 5 ohms? GO to B15. B15 CHECK CIRCUIT 780 (DB) FOR SHORT TO GROUND REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between GEM C241-8, circuit 780 (DB), and ground.

36 Page 36 of 74 Is the resistance greater than 10,000 ohms? GO to B16. B16 CHECK CIRCUIT 780 (DB) FOR SHORT TO POWER REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between GEM C241-8, circuit 780 (DB), and ground. Is any voltage indicated? REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. B17 CHECK CIRCUIT 682 (DB) FOR OPEN GO to B17. GEM C239 Measure the resistance between mode switch C230-2, circuit 682 (DB), and GEM C239-21, circuit 682 (DB). Is the resistance less than 5 ohms? GO to B18. B18 CHECK CIRCUIT 682 (DB) FOR SHORT TO GROUND REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the resistance between GEM C239-21, circuit 682 (DB), and ground.

37 Page 37 of 74 Is the resistance greater than 10,000 ohms? GO to B19. B19 CHECK CIRCUIT 682 (DB) FOR SHORT TO POWER REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between GEM C239-21, circuit 682 (DB), and ground. Is any voltage indicated? REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. B20 CHECK BRAKE PEDAL POSITION (BPP) SWITCH INPUT MONITOR THE GEM PID BOO_GEM REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID BOO_GEM. Depress the brake pedal. Does the GEM PID BOO_GEM display ON? GO to B23. GO to B21. B21 CHECK THE VOLTAGE TO THE BPP SWITCH CIRCUIT 10 (LG/R)

38 Page 38 of 74 BPP Switch C252 Measure the voltage between BPP switch C252, circuit 10 (LG/R), and ground. Is the voltage greater than 10 volts? GO to B22. B22 CHECK THE BPP SWITCH MONITOR THE GEM PID BOO_GEM CHECK fuse junction panel 13 (15A). REPLACE if necessary. If fuse junction panel 13 (15A) is OK, REPAIR circuit 10 (LG/R). CLEAR the DTCs. TEST the system for normal operation. Verify the GEM PID BOO_GEM displays OFF. Connect a jumper wire between BPP switch C252, circuit 10 (LG/R), and circuit 511 (LG). Monitor the GEM PID BOO_GEM. Does the GEM PID display ON? B23 CHECK THE CLUTCH INTERLOCK MONITOR THE GEM PID CLTCHSW REPLACE the BPP switch; REFER to Section CLEAR the DTCs. TEST the system for normal operation. REPAIR circuit 511 (LG). TEST the system for normal operation. If the concern remains, REPLACE the GEM. REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID CLTCHSW. Verify the GEM PID CLTCHSW displays ACTIVE.

39 Page 39 of 74 Verify the GEM PID CLTCHSW displays ACTIVE. Verify that the GEM PID CLTCHSW indicates notact when the transmission is in any position other than NEUTRAL or PARK. Do the GEM PIDs display correctly? GO to B24. B24 CHECK THE DIGITAL TR SENSOR MONITOR THE GEM PID NTRL_SW DIAGNOSE the starter interrupt circuit and digital TR sensor; REFER to Section If the circuits are OK, REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID NTRL_SW. Verify the GEM PID NTRL_SW displays NTRL. Verify the GEM PID NTRL_SW displays notntrl when the transmission is in any position other than NEUTRAL. Do the GEM PIDs indicate correctly? GO to B28. GO to B25. B25 CHECK THE GROUND TO THE DIGITAL TRANSMISSION RANGE (DTR) SENSOR Digital TR Sensor C182 Measure the resistance between digital TR sensor C182-7, circuit 57 (BK), and ground. Is the resistance less than 5 ohms? GO to B26. B26 CHECK THE DIGITAL TR SENSOR MONITOR THE GEM PID NTRL_SW REPAIR circuit 57 (BK). CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID NTRL_SW.

40 Page 40 of 74 Verify the GEM PID NTRL_SW displays notntrl. Connect a jumper wire between digital TR sensor C182-7, circuit 57 (BK), and C182-8, circuit 463 (R/W). Does the GEM PID NTRL_SW indicate NTRL? B27 CHECK THE VEHICLE SPEED SENSOR (VSS) MONITOR THE GEM PID VSS_GEM REPLACE the digital TR sensor; REFER to Section A or Section B. CLEAR the DTCs. TEST the system for normal operation. REPAIR circuit 463 (R/W). CLEAR the DTCs. TEST the system for normal operation. If the concern remains, REPLACE the GEM. REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID VSS_GEM while driving the vehicle from 0 to 88.5 km/h (55 mph). Does the GEM PID VSS_GEM agree with the speedometer? GO to B30. B28 CHECK CIRCUIT 676 (PK/O) FOR OPEN GO to B28. VSS C186 Fuse Junction Panel C242 Measure the resistance between VSS C186, circuit 676 (PK/O), and fuse junction panel C242-9, circuit 676 (PK/O).

41 Page 41 of 74 Is the resistance less than 5 ohms? GO to B29. B29 CHECK CIRCUIT 679 (GY/BK) FOR OPEN REPAIR circuit 676 (PK/O). CLEAR the DTCs. TEST the system for normal operation. Fuse Junction Panel C243 Measure the resistance between VSS C186, circuit 679 (GY/BK), and fuse junction panel C243-21, circuit 679 (GY/BK). Is the resistance less than 5 ohms? GO to B30. B30 CHECK THE CIRCUITS BETWEEN THE GEM AND THE FUSE JUNCTION PANEL REPAIR circuit 679 (GY/BK). CLEAR the DTCs. TEST the system for normal operation. GEM C267 Measure the resistance between fuse junction panel C242 terminal 9 and fuse junction panel C267 terminal 10; and between fuse junction panel C243 terminal 21 and GEM C267 terminal 18. Are the resistances less than 5 ohms?

42 Page 42 of 74 REPLACE the vehicle speed sensor; REFER to Section CLEAR the DTCs. TEST the system for normal operation. REPLACE the fuse junction panel. CLEAR the DTCs. TEST the system for normal operation. B31 CHECK THE CONTACT PLATE SWITCHES MONITOR THE GEM PIDS PLATE_A, PLATE_B, PLATE_C, AND PLATE_D Monitor GEM PIDs PLATE_A, PLATE_B, PLATE_C, and PLATE_D. Place the mode switch in the 4H position and record the PIDs. Place the mode switch in the 4L position and record the PIDs. Compare the GEM PIDs with Table 4 Contact Plate Sensor Position Codes; refer to 4WD Tables. Do the GEM PIDs agree with Table 4? REPAIR the transfer case or shift motor assembly. REFER to Section B. CLEAR the DTCs. TEST the system for normal operation. B32 MONITOR THE GEM PID PLATE_A FOR OPEN GO to B32. Transfer Case Assembly C201 Trigger the GEM active command PLATE POWER to ON. Monitor the GEM PID PLATE_A.

43 Page 43 of 74 Does the GEM PID PLATE_A not indicate OPEN? GO to B34. GO to B33. B33 CHECK CIRCUIT 771 (P/Y) TO THE CONTACT PLATE SWITCH A MONITOR THE GEM PID PLATE_A Connect a jumper wire between transfer case assembly C201-5, circuit 771 (P/Y), and C201-10, circuit 762 (Y/W). Monitor the GEM PID PLATE_A. Does the GEM PID PLATE_A indicate CLOSED? REMOVE the jumper wire; GO to B39. B34 CHECK CIRCUIT 771 (P/Y) FOR SHORT TO GROUND GO to B35. Measure the resistance between GEM C241-21, circuit 771 (P/Y), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. B35 CHECK CIRCUIT 771 (P/Y) FOR OPEN REPAIR circuit 771 (P/Y). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. GEM C241 Measure the resistance between transfer case assembly C201-5, circuit 771 (P/Y), and GEM C241-21, circuit 771 (P/Y).

44 Page 44 of 74 Is the resistance less than 5 ohms? GO to B36. B36 CHECK CIRCUIT 771 (P/Y) FOR SHORT TO POWER REPAIR circuit 771 (P/Y). CLEAR the DTCs. TEST the system for normal operation. Measure the voltage between transfer case assembly C201-5, circuit 771 (P/Y), and ground. Is any voltage indicated? REPAIR circuit 771 (P/Y). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. B37 CHECK CIRCUIT 762 (Y/W) FOR SHORT TO POWER GO to B37. Measure the voltage between GEM C241-12, circuit 762 (Y/W), and ground. Is any voltage indicated? REPAIR circuit 762 (Y/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. B38 CHECK CIRCUIT 762 (Y/W) FOR OPEN GO to B38. Measure the resistance between GEM C241-12, circuit 762 (Y/W), and transfer case assembly C201-10, circuit 762 (Y/W).

45 Page 45 of 74 Is the resistance less than 5 ohms? GO to B39. B39 MONITOR THE GEM PID PLATE_B FOR OPEN REPAIR circuit 762 (Y/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Monitor the GEM PID PLATE_B. Does the GEM PID PLATE_B not indicate OPEN? GO to B41. GO to B40. B40 CHECK CIRCUIT 770 (W) TO THE CONTACT PLATE SWITCH B MONITOR THE GEM PID PLATE_B Connect a jumper wire between transfer case assembly C201-1, circuit 770 (W), and C201-10, circuit 762 (Y/W). Monitor the GEM PID PLATE_B. Does the GEM PID PLATE_B indicate CLOSED? REMOVE the jumper wire; GO to B44. B41 CHECK CIRCUIT 770 (W) FOR SHORT TO GROUND GO to B42. GEM C241 Measure the resistance between GEM C241-20, circuit 770 (W), and ground.

46 Page 46 of 74 Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. B42 CHECK CIRCUIT 770 (W) FOR OPEN REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. GEM C241 Measure the resistance between transfer case assembly C201-1, circuit 770 (W), and GEM C241-20, circuit 770 (W). Is the resistance less than 5 ohms? GO to B43. B43 CHECK CIRCUIT 770 (W) FOR SHORT TO POWER REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. Measure the voltage between transfer case assembly C201-1, circuit 770 (W), and ground. Is any voltage indicated?

47 Page 47 of 74 REPAIR circuit 770 (W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the system for normal operation. B44 MONITOR THE GEM PID PLATE_C FOR OPEN REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for normal operation. Monitor the GEM PID PLATE_C. Does the GEM PID PLATE_C not indicate OPEN? GO to B46. GO to B45. B45 CHECK CIRCUIT 764 (BR/W) TO THE CONTACT PLATE SWITCH C MONITOR THE GEM PID PLATE_C Connect a jumper wire between transfer case assembly C201-9, circuit 764 (BR/W), and C201-10, circuit 762 (Y/W). Monitor the GEM PID PLATE_C. Does the GEM PID PLATE_C indicate CLOSED? B46 CHECK CIRCUIT 764 (BR/W) FOR SHORT TO GROUND REMOVE the jumper wire; GO to B49. GO to B47. GEM C241 Measure the resistance between GEM C241-19, circuit 764 (BR/W), and ground. Is the resistance greater than 10,000 ohms? REPLACE the GEM; REFER to Section CLEAR the DTCs. TEST the system for