U1120-LOST WHEEL DISTANCE MESSAGE
U1120-LOST WHEEL DISTANCE MESSAGE
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Powertrain Control Module (PCM) receives the vehicle speed signal over the CAN C bus from the Anti-lock Brake Module.
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When Monitored:
Ignition on.
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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.
Possible Causes |
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| CAN C BUS CIRCUIT OPEN OR SHORTED |
| ANTI-LOCK BRAKE MODULE |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
| 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. |
| 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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Diagnosis and Testing).
No
- (Refer to 29 - Non-DTC Diagnostics/Communication - Diagnosis and Testing) and perform the Stored Lost Communication DTCs diagnostic procedure.
- Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).