OBD-II code · Network
U0901 Invalid Data from Ion Sense Module
A receiving module detected implausible data from the ion sense module (used for misfire/knock detection via ionisation current at the spark plug). Per-cylinder ion current values fail plausibility checks and are rejected.
Is it safe to drive with U0901?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule internal fault or sensor input drift
- PossibleSoftware version mismatch after replacement
- Less likelyGateway module routing CAN messages incorrectly
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Ion Sense Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.