What it means
Electrical fault detected in the third cooling fan control circuit. With one stage of cooling lost, engine and A/C condenser cooling capacity is reduced, particularly at low vehicle speeds.
At a glance
- Usually lights the check-engine light
How it works
Some vehicles use several fan stages or circuits to vary cooling airflow. The control module monitors the third fan control circuit and sets P0482 when it detects an electrical fault in that circuit, which can leave one stage of radiator and A/C condenser cooling unavailable.
Common causes
Most likely first.
- Fan relay failed
- Fan motor failed
Symptoms
- Check-engine light on
- Engine temperature may rise, especially at low speeds or while idling
- Air conditioning may cool poorly when stopped
- Cooling fan may not run when expected
How to diagnose it
- Check freeze-frame data and live coolant temperature, then confirm whether the third fan stage is being commanded when the engine is warm or the A/C is on.
- With the engine off, inspect the third fan circuit’s relay, connectors, and wiring for corrosion, heat damage, loose terminals, or chafing.
- Check the fan fuse and relay operation, and compare the relay’s power, ground, and control signals with the manufacturer’s specification.
- Test the third fan motor for an open or seized condition and verify that it operates when supplied through an appropriate protected test circuit.
- If the motor and relay test correctly, check continuity and shorts in the third-stage control wiring between the relay and control module.
Common fixes
- Clean and secure corroded or loose third fan circuit connections.
- Replace a failed third-stage fan relay.
- Repair damaged wiring or a failed fuse connection in the third fan circuit.
- Replace the third fan motor if it is seized or fails its electrical test.
Can I keep driving?
Avoid extended idling, slow traffic, and using the A/C if engine temperature is rising; one cooling stage may be unavailable. Stop safely if the temperature warning appears, since overheating can damage the engine.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.