What U0431 means
Other modules receive implausible body status data (e.g. all doors reported closed while ajar).
How the engine computer detects it
Comfort and lighting features can behave inconsistently.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- BCM software version mismatch Possible
- Gateway module routing CAN messages incorrectly Less likely
- CAN terminating resistor (120 Ω) drifted out of spec Less likely
How to diagnose U0431
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: body control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- U
- Network
- 0
- Generic (SAE) code
- 431
- Specific fault
Questions drivers ask
Can I drive with code U0431?
It depends on which module stopped communicating. If the car drives normally, drive carefully to a shop. If the engine, transmission, brakes or steering act up, or many warning lights come on at once, stop and have it towed.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.