OBD-II code · Network
U0400 Invalid Data Received
A controller flags that the data received over the bus is implausible without identifying a specific source. Used as a generic placeholder when the more specific U04xx codes do not apply.
Is it safe to drive with U0400?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyMarginal signal on bus
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Can Bus Wiring, Control Module
Related codes
- U0352Software Incompatibility With NOx Sensor C
- U0353Software Incompatibility With Ion Sense Module
- U0354Software Incompatibility With Hybrid/EV Battery Inductive Charger Control Module
- U0401Invalid Data Received from ECM/PCM
- U0402Invalid Data Received from TCM
- U0403Invalid Data Received from Transfer Case Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.