OBD-II code · Network
U0401 Invalid Data Received from ECM/PCM
The ECM/PCM is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Implausible engine data can force limp mode or stall the engine. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.
Is it safe to drive with U0401?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- PossibleECM software bug or outdated calibration
- PossibleECM internal sensor or processing fault
- PossibleCAN corruption causing checksum errors
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
- 1–5 h
- Emissions test
- Likely to fail
- Parts involved
- Ecm, Can Bus Wiring
Related codes
- U0353Software Incompatibility With Ion Sense Module
- U0354Software Incompatibility With Hybrid/EV Battery Inductive Charger Control Module
- U0400Invalid Data Received
- U0402Invalid Data Received from TCM
- U0403Invalid Data Received from Transfer Case Control Module
- U0404Invalid Data Received from Gear Shift Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.