P0485
Cooling Fan Power/Ground Circuit
A fault is detected in the supply or ground path of the cooling fan circuit. Voltage drops or open ground prevent reliable fan operation.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Ground connection open or corrodedCommon
- Power supply circuit faultPossible
- Connector damagedLess likely
Parts involved
- Cooling Fan
- Cooling Fan Relay
P0485 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.