Possible causes

– Faulty fan control relay
– Faulty cooling fan
– Fan control relay harness is open or shorted
– Fan control relay circuit poor electrical connection
– Fan cooling fan harness is open or shorted
– Fan cooling fan circuit poor electrical connection

When is the code detected?

The P0485 code is detected when the Powertrain Control Module (PCM) detects that the commanded state of the driver and the actual state of the control circuit do not match.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Engine overheating

P0485 Description

The electric cooling fan is controlled by the Engine Control Module (ECM) through the cooling fan relay based on inputs from the following components:
– The engine coolant temperature (ECT) sensor
– The intake air temperature (IAT) sensor
– The A/C selector switch
– The A/C refrigerant pressure sensor
– The vehicle speed sensor (VSS)
The ECM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. The cooling fan relay will be commanded ON when the following conditions are met:
– The engine coolant temperature reaches 106