Radiator Cooling Fan Control Module: Description and Operation

DESCRIPTION
The cooling system utilizes two plastic fans. The fans are driven by individual electric motors which are controlled electronically by the Powertrain Control Module (PCM3. Fan speed is variable and is controlled based on engine coolant and A/C high pressure refrigerant temperature.

OPERATION
Both fans are commanded "ON" at low speed at a calibrated engine coolant or A/C high pressure refrigerant temperature increases and reaches full power at a higher calibrated engine coolant or A/C high pressure refrigerant temperature. Undesirable on off operation of the fans is eliminated by utilizing turn off temperatures lower than the turn on temperatures. When the system demands more cooling, the left fan will operate at high speed until the demand has been met.

NOTE: Cooling fan(s) are operated by a relay(s) and switches.

WARNING: An electric fan under the hood can start up even when the engine is not running and can injure you. Keep hands, clothing and tools away from any underhood electrical fan.