Invalid Data Received From Body Control Module A
What it means
U0431 is a network communication code: a module is receiving data from body control module 'A' (BCM) that is corrupt, missing, or out of range. The 'A' designation identifies a specific BCM on vehicles with more than one. The BCM manages lights, locks, wipers, and many convenience features, so invalid data can cause several of them to misbehave at once. A weak battery or bad ground is a common cause, so start there before condemning the module.
Can I keep driving? Usually drivable, but body electrical features — lights, wipers, locks, or warnings — may misbehave, so verify safety items before longer trips.
Common symptoms
What you'll notice
- Warning lights or messages for multiple systems
- Erratic exterior/interior lighting, wipers, or turn signals
- Power locks, windows, or other convenience features not responding
- Other modules reporting communication faults at the same time
Common causes
Most likely first
- Internal fault in body control module 'A' (BCM) sending corrupt dataLikely
- Wiring or connector faults on the communication bus to the BCMCommon
- Low battery voltage or a poor ground upsetting BCM operationCommon
- Software mismatch after a BCM replacement or reflashLess often
How to diagnose & fix
Work through it in order
- Scan every module and record freeze-frame data; address lost-communication codes first.
- Test battery voltage and BCM grounds — weak power commonly corrupts BCM data.
- Inspect BCM connectors and bus wiring for corrosion, water intrusion, or backed-out pins.
- Check the CAN bus for shorts or opens affecting the BCM.
- If power and wiring check out, suspect the BCM; confirm and reflash or replace per manufacturer procedure.
FAQ
Quick answers
Is it safe to drive with U0431?+
Can I just clear U0431?+
Related codes
Often seen with U0431
Read & clear U0431 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.