U0406Invalid Data Received From Fuel Injector Control Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U0406 means a receiving controller, normally the ECM/PCM, gets messages from the fuel injector control module that arrive but fail its checks: wrong counter, checksum, range or a signal marked invalid. Ford's 2012 OBD summary shows the U04xx principle with U0401: the TCM stores it when the ECM sends invalid or faulted torque or pedal data. A separate injector module exists only on some designs; GM's 2013 bi-fuel CNG Silverado/Sierra uses an FICM that switches the injectors and passes rail pressure and temperature to the ECM over serial data. No manufacturer documents U0406 publicly. As fuel delivery affects emissions, CARB requires such inputs to be monitored and a MIL is likely. U0105 means lost contact, U0306 a software mismatch.
- What you may notice
- Check engine light on
- Rough running, misfire or hard start
- Reduced power
- Likely causes
- PossibleCorroded or loose connector, damaged bus wire to the injector module
- PossibleLow supply voltage at the injector module
- PossibleSoftware levels of injector module and ECM do not match
- RareInjector control module internally faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.