What does it mean?
P1484 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cooling Fans Circuit Short to Ground or Open Circuit .
Symptoms
- MIL on
- One fan speed is missing, or the fans never run at all
- Coolant temperature rises whenever the vehicle is stationary
- A/C air warms up at idle and improves as soon as the vehicle moves
- In the stuck-on failure, the fans run continuously and drain the battery
Likely causes
- Fan control circuit open or shorted to ground between the module and the fan relay
- Fan relay with an open coil or welded contacts
- Fan motor connector corroded or burnt at the terminals
- Harness chafed where it crosses the radiator support or fan shroud
- Fan motor internally open, so the module sees no load on the circuit
- Corroded body ground point or a broken ground strap for the fan circuit
- Module output driver failure
How to fix it
- Use the scan tool to command each fan output and identify which one fails to respond
- Check the relevant fuse and relay, substituting a known good relay where possible
- With the relay removed, test the control circuit for a short to ground
- Check continuity from the relay socket through to the module pin
- Apply power directly to the fan motor with a fused lead to confirm the motor runs
- Clean and repair corroded terminals and ground points
- Replace the relay or fan motor, or repair the harness, then retest fan staging