Cooling Fan Motor Control

The ECM controls the cooling fan motor by grounding the cooling fan relay. When the relay coil circuit is grounded, the relay closes allowing current to flow to the cooling fan motor.

The ECM operates the cooling fan relay based on the reading from the ECT sensor. Under normal operating conditions, the cooling fan operated whenever the ECT is greater than 102°C (216°F) or the A/C relay is commanded On below 97 km/h (60 mph). The cooling fans will turn Off when the temperature drops below 99°C (210°F). The cooling fan will continue to operate for a maximum of seven minutes after the ignition has been turned Off if the following conditions are met.

^ Coolant temp is greater than 100°C (212°F) and intake temperature is greater than 77°C (171°F)
^ Coolant temp is greater than 104°C (219°F) and intake temperature is greater than 55°C (131°F)
^ Coolant temp is greater than 105°C (221°F)