P2C40
Fan 4 Control Circuit High
The control circuit of cooling fan 4 reports a control circuit high condition. Fan operation cannot be commanded reliably.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Control wire shorted to B+Common
- Relay coil openPossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Cooling Fan 4
- Fan Relay 4
- ECM
P2C40 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.