P1660
Cooling Fan Control Circuit
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–56 (est.)
Symptoms
- Cooling fan does not turn on
- Engine overheating
- Check Engine Light Is On
- Unstable engine operation at high temperatures
- The fan runs constantly or does not turn off
Causes
- Open or short circuit in control circuit
- Faulty fan relay
- Blown fuse
- Fan motor problems
- Engine control unit (ECU) malfunction
How to Fix
- Check fan circuit fuses
- Check fan relay
- Inspect the wiring harness for damage
- Check the operation of the fan motor
- Check control signals from the ECU