Cooling

P0481 — Cooling Fan 2 Control Circuit Malfunction

Severity: medium Drive with care, to a shop

What P0481 means

The engine control module switches the second radiator fan through a relay or driver and monitors that circuit. P0481 sets when the circuit does not behave as commanded, such as an open, a short to ground or power, or a failed fan or relay. The fan may not run at all, or it may run all the time.

Symptoms

  • Check Engine light on
  • Overheating warning or rising temperature in traffic
  • Fan 2 does not turn on
  • Fan runs constantly, even on a cold engine
  • Weak A/C performance when stopped

Possible causes

  1. Failed fan 2 motor
  2. Bad fan relay or blown fuse
  3. Corroded connector at the fan shroud
  4. Short or open in the wiring harness
  5. Poor ground on the fan circuit
  6. Faulty fan control module
  7. Rarely, a failed PCM

How to diagnose

  1. Scan for codes and freeze frame data, and note any other cooling-related codes
  2. Check the fan fuse and relay, and swap in a known good relay if possible
  3. Command the fans on with a scan tool and see whether fan 2 responds
  4. Inspect the connector and harness near the fan shroud for corrosion, chafing or melting
  5. Test for power and ground at the fan connector with a multimeter
  6. Power the motor directly and confirm it spins freely
  7. Test the control wire from the PCM or relay to the connector for opens and shorts
  8. Check coolant level, condition and thermostat operation

Common fixes

  • Replace the fan relay or fuse
  • Clean the terminals or replace a damaged connector
  • Repair or replace the damaged section of harness
  • Replace the fan motor or the whole fan assembly
  • Replace the fan control module, and the PCM only after ruling out everything else

Questions and answers

What does P0481 mean?

It means a fault in the control circuit for the second cooling fan. The computer sees that the circuit is not working as commanded, due to wiring, a relay or the fan motor.

Can I drive with P0481?

Only in a limited way and with low load while watching the temperature. In traffic or hot weather the engine can overheat, so do not put off the repair.

What is the easiest way to find the cause of P0481?

Start with the fuse and relay, then check the connector at the fan and power the motor directly. This separates a bad motor from a wiring problem.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.