U1113C-LOST WHEEL SPEED MESSAGES

For a complete wiring diagram Refer to Section 8W.

Theory of Operation

The ABS communicates with other controllers over the CAN C bus. The AWD Module continuously monitors the bus activity and receives the messages it needs. The CAN C bus is also used to communicate AWD Control Module MIL status to the Engine Controller, therefor if the Engine Controller is unable to communicate with the AWD Control Module, the Engine Controller will light the MIL.

When Monitored:
Ignition on.
Set Condition:
The AWD does not receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus.

Possible Causes

CAN C BUS CIRCUIT OPEN OR SHORTED

ANTI-LOCK BRAKE (ABS) MODULE

ALL WHEEL DRIVE (AWD) CONTROL MODULE

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING) .

Diagnostic Test

1. ACTIVE DTC

NOTE: For vehicle communication problems, use the scan tool to refer to the Network Review Screen. The screen depicts a high level view of the vehicle network. Fault and problem areas appear in red. Selecting any of the network components allows access to the source of the problem.

Ignition on, engine not running.
With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

Go To 2

Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Perform AWD Control Module VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE/ELECTRONICALLY CONTROLLED CLUTCH - STANDARD PROCEDURE)

2. U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE ALSO SET

With a scan tool, select View DTCs.

Is the DTC U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE also set?

Yes

Perform the diagnostic procedure for U0121-LOST COMMUNICATION WITH ANTI-LOCK BRAKE MODULE.

Perform AWD Control Module VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE/ELECTRONICALLY CONTROLLED CLUTCH - STANDARD PROCEDURE)

Replace the AWD Control Module in accordance with the Service information.
Perform AWD Control Module VERIFICATION TEST. (Refer to 3 - DIFFERENTIAL & DRIVELINE/ELECTRONICALLY CONTROLLED CLUTCH - STANDARD PROCEDURE).