Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Normal Operation and Fault Conditions
With the ignition ON, the PCM sends messages to the ABS module through the GWM over the HS-CAN 1. If the ABS module does not receive these messages within a certain time frame (usually less than 1 second), the ABS module sets DTCs. For information on the messages sent to the ABS module by the PCM, refer to the Network Message Chart in Description and Operation of DESCRIPTION AND OPERATION .
| DTC | Description | Fault Setting Conditions |
|---|---|---|
| U0100:00 | Lost Communication With ECM/PCM "A": No Sub Type Information | This DTC sets if the ABS module does not receive any messages from the PCM. |
| U0401:00 | Invalid Data Received From ECM/PCM "A": No Sub Type Information | This DTC sets in continuous memory if the brake pedal position message, driven wheel torque message, the accelerator pedal position message or the brake pedal position message from the PCM (sent through the GWM) contains invalid information. |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.