Network
generic / SAE
U05A9
NOx Sensor C Received Invalid Data From ECM/PCM
NOx sensor C (smart sensor with own ECU) received implausible data from the ECM/PCM. Engine load, fuel rate or temperature data needed for the sensor's internal compensation fails plausibility checks; the sensor reports degraded readings.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number5 / A9
Possible causes
- ECM/PCM internal fault or sensor input drift high
- Software version mismatch after replacement medium
- Gateway module routing CAN messages incorrectly low
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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 200–2500 €
- Estimated time: 1–5 h
- Component: nox sensor c
- Component: ecm
- MIL / check engine light
- emissions-relevant
- drive cycle required
- limp mode possible
Sources
References
sae:J2012