P0C31
Inverter B Cooling System Performance
The inverter B cooling system does not maintain target temperatures under load. Coolant flow reduced, fan failure, or radiator fouling.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Common causes
Ordered by how often each turns out to be the cause.
- Coolant flow reducedCommon
- Cooling fan failurePossible
Parts involved
- Inverter B
- Inverter B Cooling
P0C31 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.