U0431 code meaning
Invalid Data Received From Body Control Module A
What U0431 means
U0431 points at body control module A on vehicles that split body functions over several controllers; with a single BCM the code is U0422, and units B to E have U0443 to U0446. Mitsubishi documents it in the all-wheel-drive ECU, which reads body data from the ETACS unit, among them the stop light switch, and sets U0431 when that signal is abnormal; CAN lines and ETACS codes are checked before the AWD unit is replaced. Its bulletin TSB-18-23-001 (2014-18 Outlander with AWC, built before 1 March 2018) reflashes the AWC ECU when the 4WD warning comes on with U0431. Audi finds U043100 in the gateway of 2023-24 e-tron and Q8 e-tron models with an ignition that refuses to switch on, and updates comfort central module J393. U0141 is lost contact, U0331 software.
U0431 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyWorkshop only
- Typical labor0.3 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0431
- All-wheel-drive or 4WD warning lamp on
- Ignition or comfort functions do not switch on
- Further body-related warnings in the cluster
Common causes of U0431
- Most likelySoftware of the receiving module (e.g. AWD unit) misreads body data, reflash needed
- PossibleBody control module A software or coding faulty
- Less likelySupply or ground problem at body control module A
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Body control moduleCAN bus wiring
What each part of U0431 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 31 | The exact fault in that area. |
What to do next
- Note U0431 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U0431
What does U0431 mean?
U0431 means "Invalid Data Received From Body Control Module A". U0431 points at body control module A on vehicles that split body functions over several controllers; with a single BCM the code is U0422, and units B to E have U0443 to U0446. It is a generic code, so it means the same on every make.
Is it safe to drive with U0431?
U0431 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0431 fail an emissions test?
U0431 is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U0431 to fix?
Difficulty: workshop only. A typical repair takes 0.3 to 2 hours of work. This is a job for a workshop.
Will U0431 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.