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.
Diagnostic Aids
If the vehicle speed signal is the cause of the concern, the PSCM uses a default vehicle speed value and the level of steering assistance does not change as vehicle speed increases or decreases.
DTC U0401:00 indicates an engine speed or vehicle speed message concern. The module reporting this DTC is not the problem module. Do not install a new PSCM as part of the repair for PSCM DTC U0401:00. The PSCM sends a message to the IPC to display STEERING ASSIST FAULT SERVICE REQUIRED in the message center.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.