U1120

U1120-LOST WHEEL DISTANCE MESSAGE

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

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

- When Monitored:
Ignition on.

- Set Condition:
The Powertrain Control Module (PCM) doesn't receive a vehicle speed signal from the Anti-lock brake Module over the CAN C bus. One Trip fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. PCM Pre-Diagnostic Troubleshooting Procedure.

Diagnostic Test

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With the scan tool, select View PCM DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. PCM Intermittent Condition Test.

2. U0121-LOST COMMUNICATION WITH ABS MODULE ALSO SET
1. 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. Totally Integrated Power Module (TIPM)
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Replace and program the Powertrain Control Module. Testing and Inspection
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.