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 wheel distance message from the Anti-lock brake Module or BCM (NON-ABS) over the CAN C bus.
| 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 or BCM (NON-ABS).
Diagnostic Test
1. ACTIVE DTCIgnition on, engine not running.
With the scan tool View Powertrain 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/P0140–LOST COMMUNICATION WITH BCM ALSO SET
NOTE: If the vehicle is not equipped with ABS the VSS signal will come from the BCM.
With the scan tool, read the appropriate module for DTCs.
Is the U0121-LOST COMMUNICATION WITH ABS MODULE/P0140–Lost Communicate With BCM also set?
Yes
- Perform the appropriate diagnostic test. Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No
- Replace and program the Powertrain Control Module per Service Information.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)