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 SECM through the GWM and the SASM over the HS-CAN 2. The SASM and the SECM communicate over a private CAN. If the SECM does not receive these messages within a certain time frame, the SECM sets a DTC. For information on the messages sent to the SECM by the PCM, refer to the Network Message Chart in the Description and Operation in Power Steering article
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| U0100:00 | Lost Communication With ECM/PCM "A": No Sub Type Information | Sets when the SECM detects any of the PCM messages is missing. This can be due to a PCM failure, a circuit failure on the HS-CAN or an excessive load on the network. |
NO RELATED
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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.