P2B31
Fan 2 Performance/Stuck Off
Cooling fan 2 is commanded on but does not produce the expected airflow. Mechanical seizure, broken motor, or relay failure.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Fan motor seized or burned outCommon
- Fan relay contacts oxidisedPossible
- Carbon or debris buildup preventing free movementLess likely
Parts involved
- Cooling Fan 2
- Fan Relay 2
- ECM
P2B31 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.