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

Instrumentation, Message Center and Warning Chimes

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 (Electronic Locking Differential) mode, the TCCM (Transfer Case Control Module) sends the IPC (Instrument Panel Cluster) a message to turn on the ELD (Electronic Locking Differential) message center indicator. If the vehicle is shifted out of ELD (Electronic Locking Differential) mode, the TCCM (Transfer Case Control Module) sends the IPC (Instrument Panel Cluster) a message to turn off the ELD (Electronic Locking Differential) message center indicator, informing the driver that the vehicle has shifted out of ELD (Electronic Locking Differential) mode.

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

This pinpoint test is intended to diagnose the following:

- ELD (Electronic Locking Differential) concern

- TCCM (Transfer Case Control Module)

- IPC (Instrument Panel Cluster)

PINPOINT TEST AF : THE ELD (Electronic Locking Differential) INDICATOR IS NEVER/ALWAYS ON

AF1 CHECK THE 4X4 OPERATION

- Start the engine.

- Shift the transfer case into 4WD (Four-Wheel Drive) mode.

Does the transfer case shift into 4WD (Four-Wheel Drive) mode?

Yes
GO to AF2.

No
To diagnose 4WD (Four-Wheel Drive) concerns, REFER to Transfer Case.

AF2 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

- Check for recorded DTCs from the IPC (Instrument Panel Cluster) self-test.

Is DTC U0102:00 recorded?

Yes
GO to Pinpoint Test BC. Pinpoint Test BC: DTC U0102:00
No
GO to AF3.

AF3 RETRIEVE THE RECORDED DTCs FROM THE TCCM (Transfer Case Control Module) SELF-TEST

- Check for recorded TCCM (Transfer Case Control Module) DTCs from the self-test.

Are any DTCs recorded?

Yes
REFER to Transfer Case.

No
GO to AF4

AF4 CARRY OUT THE IPC (Instrument Panel Cluster) WARNING LAMPS COMMAND USING THE SCAN TOOL

- Ignition ON.

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

- Select the IPC (Instrument Panel Cluster) all lamps (ALL_LAMP) active command. Command all the indicators on and off. Observe the ELD (Electronic Locking Differential) indicator.

Does the ELD (Electronic Locking Differential) indicator illuminate when commanded on, and turn off when commanded off?

Yes
INSTALL a new TCCM (Transfer Case Control Module).

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