Pinpoint Test AD: Rear Wheels Binding When Turning Corners With The ELD (Electronic Locking Differential) OFF

Electronic Locking Differential (ELD) System

Pinpoint Test AD: Rear Wheels Binding When Turning Corners With the ELD (Electronic Locking Differential) OFF


Normal Operation

When the MSS (Mode Select Switch) is engaged to lock the rear differential, a PWM (Pulse Width Modulated) signal is sent to the ELD (Electronic Locking Differential) field coil by the TCCM (Transfer Case Control Module) through the differential lock control circuit. This PWM (Pulse Width Modulated) signal is initially 98% duty cycle to lock the differential and decreases to 40% duty cycle once the differential is locked. If the differential does not lock, the TCCM (Transfer Case Control Module) continues to send the signal for a set amount of time. Once the differential is locked, the indicator will illuminate steady.

- DTC P187E:00 (Differential Lock-Up Control Circuit High: No Sub Type Information)- The TCCM (Transfer Case Control Module) sends a signal to lock the differential. This DTC sets when the TCCM (Transfer Case Control Module) C2371B-9 senses that the differential lock control circuit is shorted to battery voltage. The differential is constantly engaged.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- ELD (Electronic Locking Differential) field coil

- TCCM (Transfer Case Control Module)

PINPOINT TEST AD : REAR WHEELS BINDING WHEN TURNING CORNERS WITH THE ELD (Electronic Locking Differential) OFF

NOTE:
Make sure the battery is fully charged before carrying out this pinpoint test.

AD1 CHECK FOR VOLTAGE TO THE ELD (Electronic Locking Differential) FIELD COIL

- Ignition OFF.

- Disconnect: ELD (Electronic Locking Differential) Field Coil.

- Ignition ON.

- Set the MSS (Mode Select Switch) in 2H (ESOF (Electronic Shift-On-The-Fly) or 2 speed-torque-on-demand).

- Set the MSS (Mode Select Switch) in OFF (2WD (2-Wheel Drive) ).

- Measure the voltage between ELD (Electronic Locking Differential) field coil C4359-1, circuit CCF31 (BN/VT), harness side and ground.






Is any voltage present?

Yes
GO to AD2.
No
REFER to Differential Assembly &/or Axle Shaft Assembly to repair the rear differential. CLEAR the DTCs. TEST the system for normal operation.

AD2 CHECK THE ELD (Electronic Locking Differential) FIELD COIL CIRCUIT FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: TCCM (Transfer Case Control Module) C2371B.

- Ignition ON.

- Measure the voltage between field coil C4359-1, circuit CCF31 (BN/VT), harness side and ground.






Is any voltage present?

Yes
REPAIR circuit CCF31 (BN/VT). CLEAR the DTCs. TEST the system for normal operation.
No
GO to AD3.

AD3 CHECK THE TCCM (Transfer Case Control Module) REAR LOCKING DIFFERENTIAL PWM (Pulse-Width Modulation) OUTPUT CONTROL (DIFF_PWM_OS) PID

- Ignition OFF.

- Connect: ELD (Electronic Locking Differential) Field Coil.

- Connect: TCCM (Transfer Case Control Module) C2371B.

- Ignition ON.

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

- With the MSS (Mode Select Switch) in 2H or OFF (depending upon vehicle option content), monitor the DIFF_PWM_OS PID.

Does the DIFF_PWM_OS PID read OFF?

Yes
GO to AD4.
No
INSTALL a new MSS (Mode Select Switch). REFER to Mode Select Switch (MSS) . CLEAR the DTCs. TEST the system for normal operation.

AD4 CHECK FOR CORRECT TCCM (Transfer Case Control Module) OPERATION

- Ignition OFF.

- Disconnect and inspect all TCCM (Transfer Case Control Module) connectors.

- Repair:
- corrosion (install new connector or terminals - clean module pins)

- damaged or bent pins - install new terminals/pins

- pushed-out pins - install new pins as necessary


- Connect all TCCM (Transfer Case Control Module) connectors. Make sure they are seated correctly.

- Operate the system and verify the concern is still present.

Is the concern still present?

Yes
INSTALL a new TCCM (Transfer Case Control Module). REFER to Transfer Case Control Module (TCCM) . TEST the system for normal operation.
No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. ADDRESS the root cause of the connector or pin issues.