Pinpoint Test I: Electronic Shift-On-The-Fly (ESOF) Functional Test

Four Wheel Drive (4WD) Systems - Electronic Shift

Pinpoint Test I: Electronic Shift-On-The-Fly (ESOF) Functional Test

Normal Operation

When operating in 4H or 4L mode, the transfer case and both IWEs (Integrated Wheel Ends) are locked. When in 4L mode, the transfer case low range gear set provides an additional 2.64 gear reduction. When operating in 2H mode, the transfer case and both IWEs (Integrated Wheel Ends) are unlocked.

This pinpoint test is intended to diagnose the following:

- 4WD (Four-Wheel Drive) system and/or related components

PINPOINT TEST I : ESOF (Electronic Shift-On-The-Fly) FUNCTIONAL TEST

WARNING: When directed to drive the vehicle as part of this test, drive the vehicle on a hard surface in an area without traffic to prevent a crash. Failure to follow these instructions may result in personal injury.
NOTE:
4X4 high/low (4H/4L) is not intended for driving on hard/dry surfaces.

I1 CHECK FOR IPC (Instrument Panel Cluster) DTCs

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: Self-Test- IPC (Instrument Panel Cluster).

Are any DTCs present?

Yes
If DTC U0102:00 is retrieved, REFER to Information Bus to diagnose lost communication with TCCM (Transfer Case Control Module). For all other DTCs, REFER to Instrument Panel, Gauges and Warning Indicators.
No
GO to I2.

I2 CHECK 2H OPERATION

- Switch the MSS (Mode Select Switch) to 2H while monitoring the message center.

Does the message center display 4X2 for approximately 4 seconds?

Yes
GO to I5.
No
GO to I3.

I3 CHECK FOR TCCM (Transfer Case Control Module) DTCs

- Enter the following diagnostic mode on the scan tool: Self-Test- TCCM (Transfer Case Control Module).

Are any DTCs present?

Yes
REFER to the TCCM (Transfer Case Control Module) DTC Chart Four Wheel Drive (4WD) Systems - Electronic Shift.
No
GO to I4.

I4 CHECK FOR WIND-UP IN 2H

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

Is wind-up present in turns?

Yes
GO to Pinpoint Test B Pinpoint Test B: The Vehicle Does Not Shift Between 2H and 4H Correctly and Grinding Noise Heard During 4WD engagement.
No
GO to I5.

I5 CHECK 4H OPERATION

- Switch the MSS (Mode Select Switch) to 4H while monitoring the message center.

Does the message center display 4X4 HIGH?

Yes
GO to I8.
No
GO to I6.

I6 CHECK FOR TCCM (Transfer Case Control Module) DTCs

- Transmission in PARK.

- Enter the following diagnostic mode on the scan tool: Self-Test- TCCM (Transfer Case Control Module).

Are any DTCs present?

Yes
REFER to the TCCM (Transfer Case Control Module) DTC Chart Four Wheel Drive (4WD) Systems - Electronic Shift.
No
GO to I7.

I7 CHECK FOR WIND-UP IN 4H

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

Is wind-up present in turns?

Yes
GO to Pinpoint Test AB Pinpoint Test AB: DTC P185D:00.
No
GO to Pinpoint Test AC Pinpoint Test AC: DTC P187C:00 and P187D:00.

I8 CHECK FOR STRAIGHT LINE 4H WIND-UP

- Drive the vehicle on a dry, hard surface.

Is straightline wind-up present?

Yes
GO to Pinpoint Test H. Pinpoint Test H: Vehicle Pulsates Or Shudders In a Straight Line (Straight Line Driveline Wind-up)
No
GO to I9.

I9 CHECK 4H WIND-UP IN TURNS

- Drive the vehicle in 4H while turning.

Is wind-up present in turns?

Yes
GO to I10.
No
GO to Pinpoint Test B. Pinpoint Test B: The Vehicle Does Not Shift Between 2H and 4H Correctly and Grinding Noise Heard During 4WD engagement

I10 CHECK 4L OPERATION

- Bring the vehicle to a stop with the transmission in NEUTRAL and switch the MSS (Mode Select Switch) to 4L.

Does the 4X4 LOW indicator illuminate correctly?

Yes
GO to I13.
No
GO to I11.

I11 CHECK FOR TCCM (Transfer Case Control Module) DTCs

- Transmission in PARK.

- Enter the following diagnostic mode on the scan tool: Self-Test- TCCM (Transfer Case Control Module).

Are any DTCs present?

Yes
REFER to the TCCM (Transfer Case Control Module) DTC Chart Four Wheel Drive (4WD) Systems - Electronic Shift.
No
GO to I12.

I12 CHECK FOR WIND-UP IN 4L

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

Is wind-up present in turns?

Yes
GO to Pinpoint Test A. Pinpoint Test A: The 4WD (Four-Wheel Drive) Indicators Do Not Operate Correctly
No
GO to Pinpoint Test C. Pinpoint Test C: The Vehicle Does Not Shift Between 4H and 4L Modes Correctly

I13 CHECK FOR 4L WIND-UP IN TURNS

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

Is wind-up present and 4L functioning?

Yes
GO to I14.
No
CHECK for TCCM (Transfer Case Control Module) DTCs. REFER to the TCCM (Transfer Case Control Module) DTC Chart Four Wheel Drive (4WD) Systems - Electronic Shift. If no DTCs are present, GO to Pinpoint Test C. Pinpoint Test C: The Vehicle Does Not Shift Between 4H and 4L Modes Correctly

I14 CHECK 4L TO 2H SHIFT

- With the vehicle at a stop and transmission in NEUTRAL, switch the MSS (Mode Select Switch) from 4L to 2H.

Does the message center display 4X2 for approximately 4 seconds?

Yes
GO to I17.
No
GO to I15.

I15 CHECK FOR TCCM (Transfer Case Control Module) DTCs

- Transmission in PARK.

- Enter the following diagnostic mode on the scan tool: Self-Test- TCCM (Transfer Case Control Module).

Are any DTCs present?

Yes
REFER to the TCCM (Transfer Case Control Module) DTC Chart Four Wheel Drive (4WD) Systems - Electronic Shift.
No
GO to I16.

I16 CHECK FOR WIND-UP IN 2H

- Switch the MSS (Mode Select Switch) to 2H.

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

Is wind-up present in turns?

Yes
GO to Pinpoint Test C. Pinpoint Test C: The Vehicle Does Not Shift Between 4H and 4L Modes Correctly
No
GO to Pinpoint Test A. Pinpoint Test A: The 4WD (Four-Wheel Drive) Indicators Do Not Operate Correctly

I17 CHECK FOR TRANSFER CASE DISENGAGEMENT

- With the vehicle in NEUTRAL, position it on a hoist.

- Rotate the rear driveshaft while observing the front driveshaft.

Does the front driveshaft rotate?

Yes
REFER to Transfer Case.
No
GO to I18.

I18 CHECK FOR LH AND RH IWE (Integrated Wheel End) DISENGAGEMENT
NOTE: The engine must be idling during the following steps to supply the vacuum required for the IWEs (Integrated Wheel Ends) to engage and disengage.

- Start the engine.

- Rotate the LH front tire one revolution forward and one revolution backward while observing the LH front halfshaft and U-joint.

- Rotate the RH front tire one revolution forward and one revolution backward while observing the RH front halfshaft and U-joint.

Does the LH or RH front halfshaft rotate?

Yes
GO to Pinpoint Test D. Pinpoint Test D: The Front Axle Does Not Engage/Disengage Correctly
No
GO to I19.

I19 CHECK FOR IWE (Integrated Wheel End) VACUUM LEAKS

- Ignition OFF.

- Disconnect both vacuum lines from the IWE (Integrated Wheel End) solenoid.

- Using a vacuum pump, apply 508 mm (20 in) Hg of vacuum to the IWE (Integrated Wheel End) apply vacuum circuit.

- Observe the vacuum reading.

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

Yes
CHECK the IWE (Integrated Wheel End) and related components for leaks. GO to Pinpoint Test D. Pinpoint Test D: The Front Axle Does Not Engage/Disengage Correctly
No
GO to I20.

I20 CHECK 2H TO 4H SHIFT AT SPEED ABOVE 32 KM/H (20 MPH)

- Switch the MSS (Mode Select Switch) to 2H.

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

Does the transfer case shift to 4H satisfactorily?

Yes
The 4WD (Four-Wheel Drive) system is functioning correctly.
No
GO to Pinpoint Test G. Pinpoint Test G: The 4WD (Four-Wheel Drive) Does Not Engage at Speed Correctly