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Home >> Ford >> 2012 >> Mustang Base, 2D Coupe, Automatic Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 557 (Four Wheel Drive (4WD) Systems) >> Diagnosis And Testing >> Four Wheel Drive (4WD) Systems - 2-Speed Torque-On-Demand >> Pinpoint Tests >> Pinpoint Test U: Four-Wheel Drive (4WD) System Functional Test >> PINPOINT TEST U: Four-Wheel Drive (4WD) SYSTEM FUNCTIONAL TEST

PINPOINT TEST U: Four-Wheel Drive (4WD) SYSTEM FUNCTIONAL TEST

WARNING: This page is about a different car, the 2014 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: 4X4 High and 4X4 Low are not intended for driving on hard/dry surfaces; using these modes while driving on these surfaces may produce noises like intermittent clunking, but will 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 IPC message center? 

    • Yes  : GO to U2  .
    • No  : GO to  U4.
  2. U2 CHECK FOR TCCM DTCs 
    • Shift the transmission into the PARK position.
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: Self-Test - TCCM  .

    Are DTCs retrieved? 

    • Yes  : REFER to the TCCM DTC CHART  for diagnosis.
    • 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? 

  4. U4 CHECK AUTO MODE OPERATION 
    • Switch the MSS  to 4A mode.

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

    • Yes  : GO to  U7.
    • No  : GO to U5  .
  5. U5 CHECK FOR TCCM DTCs 
    • Ignition ON.
    • Enter the following diagnostic mode on the scan tool: Self-Test - TCCM  .

    Are DTCs present? 

    • Yes  : REFER to the TCCM DTC CHART  for diagnosis.
    • 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 TCCM 4WD PWM CLUTCH STATUS (4WD_CLTCH_OUT) PID 
    • Enter the following diagnostic mode on the scan tool: Data Logger - TCCM  .
    • 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 TCCM 4WD PWM CLUTCH STATUS (4WD_CLTCH_OUT) ACTIVE COMMAND 
    • Enter the following diagnostic mode on the scan tool: Data Logger - TCCM  .
    • 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 THE TCCM AVERAGE FRONT WHEEL SPEED (FRT_WHL_SPD) AND AVERAGE REAR WHEEL SPEED (REAR_WHL_SPD) PIDs 
    • Enter the following diagnostic mod e on the scan tool: Data Logger - TCCM  .
    • 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. TEST the system for normal operation.
  10. U10 CHECK THE TCCM ABSOLUTE THROTTLE POSITION (TP_TCCM) PID 
    • Enter the following diagnostic mode on the scan tool: Data Logger - TCCM  .
    • 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 ? 

  11. U11 CHECK 4H MODE OPERATION 
    • Switch the MSS  to 4H mode.

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

    • Yes  : GO to  U14.
    • No  : GO to U12  .
  12. U12 CHECK FOR TCCM DTCs 
    • Shift the transmission into the PARK position.
    • Enter the following diagnostic mode on the scan tool: Self-Test - TCCM  .

    Are DTCs retrieved? 

    • Yes  : REFER to the TCCM DTC CHART  for diagnosis.
    • No  : GO to U13  .
  13. U13 CHECK FOR WIND-UP IN 4H MODE 
    • Drive the vehicle on a dry, hard surface while executing turns.

    Is wind-up present in turns? 

  14. U14 CHECK FOR STRAIGHTLINE WIND-UP IN 4H MODE 
    • Drive the vehicle on a dry, hard surface.

    Is straightline wind-up present? 

  15. U15 CHECK WIND-UP IN TURNS IN 4H MODE 
    • Drive the vehicle in 4H mode while turning.

    Is wind-up present in turns? 

  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 IPC message center illuminate correctly? 

    • Yes  : GO to  U19.
    • No  : GO to U17  .
  17. U17 CHECK FOR TCCM DTCs 
    • Shift the transmission into the PARK position.
    • Enter the following diagnostic mode on the scan tool: Self-Test - TCCM  .

    Are DTCs retrieved? 

    • Yes  : REFER to the TCCM DTC CHART  for diagnosis.
    • No  : GO to U18  .
  18. U18 CHECK FOR WIND-UP IN 4L MODE 
    • Drive the vehicle on a dry, hard surface while executing turns.

    Is wind-up present in turns? 

  19. U19 CHECK FOR WIND-UP IN TURNS IN 4L MODE 
    • Drive the vehicle on a dry, hard surface while executing turns.

    Is wind-up present and 4L mode functioning? 

  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 message center? 

    • Yes  : GO to U21  .
    • No  : GO to  U23.
  21. U21 CHECK FOR TCCM DTCs 
    • Shift the transmission into the PARK position.
    • Release the brake pedal.
    • Enter the following diagnostic mode on the scan tool: Self-Test - TCCM  .

    Are DTCs retrieved? 

    • Yes  : REFER to the TCCM DTC CHART  for diagnosis.
    • 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? 

  23. U23 CHECK FOR TRANSFER CASE DISENGAGEMENT 
    • With the vehicle in NEUTRAL, position it on a hoist. Refer to JACKING & LIFTING .
    • Rotate the rear driveshaft while observing the front driveshaft.

    Does the front driveshaft rotate? 

  24. U24 CHECK FOR LH AND RH DISENGAGEMENT 
    NOTE: The engine must be at idle during the following steps to supply vacuum for IWE  engagement/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? 

  25. U25 CHECK FOR VACUUM LEAKS 
    • Ignition OFF.
    • Disconnect both vacuum lines from the IWE  solenoid.
    • Using a hand vacuum pump, apply 508 mm (20 in) Hg of vacuum to the IWE  apply vacuum circuit.
    • Observe the vacuum reading.

    Did the vacuum drop more than 25 mm (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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