Engine Cooling Fan: Operation

The dual cooling fans operate simultaneously and are turned on when either coolant temperature sensor or A/C pressure transducer (on compressor discharge line) sends a signal to the Powertrain Control Module (PCM). The PCM turns on the fans through low and high speed fan motor relays.

When A/C is not operating, cooling fan operation is controlled by coolant temperature sensor signal to the PCM. Signal indicates when coolant has reached a specified temperature. See COOLING FAN OPERATING TEMPERATURE  table. Fans will operate independently of coolant temperature when A/C pressure reaches a predetermined level. Fans will not operate during engine cranking, regardless of coolant temperature.