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Pinpoint Test U : 4WD System Functional Test

NOTE: 4X4 is not intended for driving on hard/dry surfaces; using 4X4 mode while driving on these surfaces may produce noises like intermittent clunking, but does not damage driveline components.

  1. U1 CHECK 2H MODE OPERATION

    • Shift the transmission into the NEUTRAL position.
    • Switch the MSS to 2H mode.

    Are there any 4WD mode indicators present in the IC message center? 

    Yes  GO to  U2.
    No  GO to  U4.

  2. U2 CHECK FOR TCCM DTC s

    • Shift the transmission into the PARK position.
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: TCCM Self-Test.

    Are DTCs retrieved? 

    Yes  REFER to the TCCM DTC Chart .
    No  GO to  U3.

  3. U3 CHECK FOR WIND-UP IN 2H MODE

    • Drive the vehicle on a dry, hard surface while executing turns.

    Is wind-up present in turns? 

    Yes  GO to Pinpoint Test P .
    No  GO to Pinpoint Test V .

  4. U4 CHECK AUTO MODE OPERATION

    • Switch the MSS to 4A mode.

    Is the 4X4 auto (4A) mode indicator on in the IC message center? 

    Yes  GO to  U7.
    No  GO to  U5.

  5. U5 CHECK FOR DTCs

    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: TCCM Self-Test.

    Are DTCs present? 

    Yes  REFER to the TCCM DTC Chart .
    No  GO to  U6.

  6. U6 CHECK FOR WIND-UP IN 4A MODE

    • Drive the vehicle on a dry, hard surface, executing turns while applying the throttle.

    Is wind-up present in turns? 

    Yes  GO to  U7.
    No  GO to  U8.

  7. U7 CHECK THE 4WD PWM CLUTCH STATUS (4WD_CLTCH_OUT) PID

    • Enter the following diagnostic mode on the scan tool: TCCM DataLogger.
    • Monitor the 4WD_CLTCH_OUT PID.

    Does the PID indicate 2 to 10% clutch application at closed throttle? 

    Yes  GO to  U8.
    No  GO to  U9.

  8. U8 CHECK FOR WIND-UP IN 4A MODE WITH 100% CLUTCH USING THE 4WD PWM CLUTCH STATUS (4WD_CLTCH_OUT) ACTIVE COMMAND

    • Enter the following diagnostic mode on the scan tool: TCCM DataLogger.
    • Command the 4WD_CLTCH_OUT to 100%.
    • Drive the vehicle on a dry, hard surface, executing turns.

    Is wind-up present in turns? 

    Yes  GO to  U9.
    No  CHECK the transfer case. REFER to Transfer Case .

  9. U9 CHECK AVERAGE FRONT WHEEL SPEED (FRT_WHL_SPD) AND AVERAGE REAR WHEEL SPEED (REAR_WHL_SPD) PIDs

    • Enter the following diagnostic mode on the scan tool: TCCM DataLogger.
    • Monitor the FRT_WHL_SPD and REAR_WHL_SPD PIDs.
    • Drive the vehicle 30 km/h (18 mph).
    • Record and compare the FRT_WHL_SPD and REAR_WHL_SPD PIDs.

    Do the FRT_WHL_SPD and REAR_WHL_SPD PID values match within 1.5 km/h (1 mph)? 

    Yes  GO to  U10.
    No  VERIFY all 4 tires are the same size and brand. INSTALL new tires as necessary. If the tires are OK, CHECK the ABS. REFER to Anti-Lock Brake System (ABS) and Stability Control and VERIFY that the 4 road tire sizes match.

  10. U10 CHECK THE ABSOLUTE THROTTLE POSITION (TP_TCCM) PID

    • Enter the following diagnostic mode on the scan tool: TCCM DataLogger.
    • Ignition ON.
    • Monitor the TP_TCCM PID.
      NOTE: The TP_TCCM PID is APP as communicated by the PCM via HS-CAN.
    • Slowly move throttle from closed throttle to WOT and observe the TP_TCCM PID.

    Does the TP_TCCM PID value vary between 0% at closed throttle and 100% at WOT ? 

    Yes  GO to  U11.
    No  CHECK the APP sensor and/or the PCM. REFER to the ENGINE CONTROLS - INTRODUCTION (EXCEPT DIESEL & HYBRID) .

  11. U11 CHECK 4H MODE OPERATION

    • Switch the MSS to 4H mode.

    Does the 4X4 (4H) indicator illuminate in the IC message center correctly? 

    Yes  GO to  U14.
    No  GO to  U12.

  12. U12 CHECK FOR DTCs

    • Shift the transmission into the PARK position.
    • Enter the following diagnostic mode on the scan tool: TCCM Self-Test.

    Are DTCs retrieved? 

    Yes  REFER to the TCCM DTC Chart .
    No  GO to  U13.

  13. U13 CHECK FOR WIND-UP IN 4H MODE

    • Drive the vehicle on a dry, hard surface while executing turns under moderate pedal input.

    Is wind-up present in turns? 

    Yes  GO to Pinpoint Test Q .
    No  GO to Pinpoint Test O .

  14. U14 CHECK FOR STRAIGHTLINE WIND-UP IN 4H MODE

    • Drive the vehicle on a dry, hard surface.

    Is straightline wind-up present? 

    Yes  GO to Pinpoint Test S .
    No  GO to  U15.

  15. U15 CHECK WIND-UP IN TURNS IN 4H MODE

    • Drive the vehicle in 4H mode while turning under moderate pedal input..

    Is wind-up present in turns? 

    Yes  GO to  U16.
    No  GO to Pinpoint Test O .

  16. U16 CHECK 4L MODE OPERATION

    • Bring the vehicle to a stop with the transmission in NEUTRAL, switch the MSS to 4L mode.

    Does the 4WD LOW (4L) indicator in the IC message center illuminate correctly? 

    Yes  GO to  U19.
    No  GO to  U17.

  17. U17 CHECK FOR DTCs

    • Shift the transmission into the PARK position.
    • Enter the following diagnostic mode on the scan tool: TCCM Self-Test.

    Are DTCs retrieved? 

    Yes  REFER to the TCCM DTC Chart .
    No  GO to  U18.

  18. U18 CHECK FOR WIND-UP IN 4L MODE

    • Drive the vehicle on a dry, hard surface while executing turns under moderate pedal input.

    Is wind-up present in turns? 

    Yes  GO to Pinpoint Test V .
    No  GO to Pinpoint Test P .

  19. U19 CHECK FOR WIND-UP IN TURNS IN 4L MODE

    • Drive the vehicle on a dry, hard surface while executing turns under moderate pedal input.

    Is wind-up present and 4L mode functioning? 

    Yes  GO to  U20.
    No  CHECK for TCCM DTC s. REFER to the Inspection and Verification procedure. If no DTC s are present, GO to Pinpoint Test P .

  20. U20 CHECK 4L MODE TO 2H MODE SHIFT

    • With the vehicle at a stop and transmission in NEUTRAL, switch the MSS from 4L mode to 2H mode.

    Are there any 4WD mode indicators present in the IC message center? 

    Yes  GO to  U21.
    No  GO to  U23.

  21. U21 CHECK FOR DTCs

    • Shift the transmission into the PARK position.
    • Release the brake pedal.
    • Enter the following diagnostic mode on the scan tool: TCCM Self-Test.

    Are DTCs retrieved? 

    Yes  REFER to the TCCM DTC Chart .
    No  GO to  U22.

  22. U22 CHECK FOR WIND-UP IN 2H MODE

    • Drive the vehicle on a dry, hard surface while executing turns.

    Is wind-up present in turns? 

    Yes  GO to Pinpoint Test P .
    No  GO to Pinpoint Test V .

  23. U23 CHECK FOR TRANSFER CASE DISENGAGEMENT

    • Rotate the rear driveshaft while observing the front driveshaft.

    Does the front driveshaft rotate? 

    Yes  REFER to Transfer Case .
    No  GO to  U24.
    24. NOTE: The engine must be at idle during the following steps to supply vacuum for IWE engagement/disengagement.

  24. U24 CHECK FOR LH AND RH IWE DISENGAGEMENT
    • Start the engine and allow to idle.
    • Rotate the LF tire one revolution forward and one revolution backward while observing the LF halfshaft and U-joint.
    • Rotate the RF tire one revolution forward and one revolution backward while observing the RF halfshaft and U-joint.

    Does the LH or RH front halfshaft rotate? 

    Yes  GO to Pinpoint Test N .
    No  GO to  U25.

  25. U25 CHECK FOR IWE VACUUM LEAKS

    • Ignition OFF.
    • Disconnect both vacuum lines from the IWE solenoid.
    • Using a hand vacuum pump, apply 508 mm-Hg (20 in-Hg) of vacuum to the IWE apply vacuum circuit.
    • Observe the vacuum reading.

    Did the vacuum drop more than 25 mm-Hg (1 in-Hg) per minute? 

    Yes  CHECK the IWE and related components for leaks. GO to Pinpoint Test N .
    No  GO to  U26.

  26. U26 CHECK 2H MODE TO 4H MODE SHIFT AT SPEED ABOVE 32 KM/H (20 MPH)

    • Switch the MSS to 2H mode.
    • Drive the vehicle on the road and shift from 2H mode to 4H mode while driving above 32 km/h (20 mph).

    Does the transfer case shift to 4H mode satisfactorily? 

    Yes  The 4WD system is functioning correctly.
    No  GO to Pinpoint Test Q .
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