U1120-LOST WHEEL DISTANCE MESSAGE

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Ignition on.
Set Condition:
The PCM doesn't receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One Trip fault.

Possible Causes

CAN C BUS CIRCUIT OPEN OR SHORTED

ANTI-LOCK BRAKE MODULE

PCM

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

Theory of Operation

The PCM receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.

Diagnostic Test

1. ACTIVE DTC

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

Is the DTC Active at this time?

Yes

Go To 2

No

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2. U0121-LOST COMMUNICATION WITH ABS MODULE ALSO SET

With the scan tool continue reading DTCs.

Is the U0121-LOST COMMUNICATION WITH ABS MODULE also set?

Yes

Follow the diagnostics for U0121-LOST COMMUNICATION WITH ABS MODULE. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING)

No

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)