What P0480 means
The engine module switches the radiator fan either through a relay, whose coil it pulls to ground, or with a PWM signal to a fan control module.
How the engine computer detects it
The circuit is an output that CARB requires to be checked continuously. P0480 concerns the control circuit of fan 1. GM sets it for an open circuit – 200 kΩ or more with the driver off, 50 of 63 samples, above 11 V, MIL after two trips – and reports a short to ground or positive as P0691/P0692; Saab models on GM technology set it after 5 s (relay) or 1 s (PWM). FCA bulletins also name it with the warning lamp. Ford's OBD summaries do not contain the code. If the fan stops, the engine can overheat in traffic and the air conditioning weakens at standstill.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on
- Radiator fan does not run, or runs constantly
- Overheating at standstill or in traffic
- Air conditioning weak at standstill
Common causes
- Fan relay (coil open) or fan control module faulty Most likely
- Connector at fan or relay corroded, water ingress or pin pushed out Most likely
- Control wire open or shorted to ground Possible
- Fan motor or fan assembly faulty Possible
- Driver in the engine module Less likely
How to diagnose P0480
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: cooling fan 1, fan relay, fan control module, engine control module.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 4
- Auxiliary emission controls
- 80
- Specific fault
Questions drivers ask
Can I drive with code P0480?
Carefully, and keep an eye on the temperature gauge. Without a working fan the engine can overheat in traffic or at idle. If the gauge climbs toward hot, pull over and switch the engine off.
Will my car pass an emissions inspection with P0480?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0480 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0480 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.