Pinpoint Tests AF: The Electronic Locking Differential (ELD) Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test AF: The Electronic Locking Differential (ELD) Indicator Is Never/Always On

Normal Operation

The Instrument Panel Cluster (IPC) receives the Electronic Locking Differential (ELD) status from the Transfer Case Control Module (TCCM) over the High Speed Controller Area Network (HS-CAN) communication bus. If the vehicle is shifted into ELD mode, the TCCM sends the IPC a message to turn on the ELD message center indicator. If the vehicle is shifted out of ELD mode, the TCCM sends the IPC a message to turn off the ELD message center indicator, informing the driver that the vehicle has shifted out of ELD mode.

If the ELD status message is missing or invalid for less than 5 seconds, the electronic locking ELD warning indicator remains in the last state (on or off), based upon the last known good ELD status message received. If the ELD status message is missing for more than 5 seconds, the IPC sets DTC U0102:00 in continuous memory and defaults the ELD warning indicator off.

This pinpoint test is intended to diagnose the following:

- ELD concern
- TCCM
- IPC

PINPOINT TEST AF: THE ELD INDICATOR IS NEVER/ALWAYS ON

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AF1 CHECK THE 4X4 OPERATION

- Start the engine.
- Shift the transfer case into 4WD mode.
- Does the transfer case shift into 4WD mode?

Yes
GO to AF2.

No
REFER to Four Wheel Drive (4WD) Systems Testing and Inspection to diagnose 4WD concerns.

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AF2 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST

- Check for recorded DTCs from the IPC self-test.
- Is DTC U0102:00 recorded?

Yes
GO to Pinpoint Test BC. Pinpoint Tests BC: DTC U0102:00

No
GO to AF3.

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AF3 RETRIEVE THE RECORDED DTCs FROM THE TCCM SELF-TEST

- Check for recorded TCCM DTCs from the self-test.
- Are any DTCs recorded?

Yes
REFER to Four Wheel Drive (4WD) Systems Testing and Inspection.

No
GO to AF4

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AF4 CARRY OUT THE IPC WARNING LAMPS COMMAND USING THE SCAN TOOL

- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger.
- Select the IPC all lamps (ALL_LAMP) active command. Command all the indicators on and off. Observe the ELD indicator.
- Does the ELD indicator illuminate when commanded on, and turn off when commanded off?

Yes
INSTALL a new TCCM. REFER to Four Wheel Drive (4WD) Systems Service and Repair.

No
INSTALL a new IPC. REFER to Instrument Panel Cluster (IPC) Instrument Panel Cluster (IPC). TEST the system for normal operation.

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