Operation

GAS ENGINES





Radiator fan operation is control by the Powertrain Control Module (PCM) with inputs from the temperature of the coolant, which is sensed by the coolant temperature sensor, and vehicle speed which is measured by the vehicle speed sensor. The PCM turns on the fan through either the high or low speed fan relay. The PCM provides a ground to the relay's control circuit. The fan relays are located in the Power Distribution Center (PDC) (2). Refer to the label beneath the PDC cover for location of fan relays.

Refer to Radiator Fan Operation Chart for fan operation specifications. For fan circuit wiring diagrams, refer to WIRING DIAGRAMS.
If the cooling fan is inoperative or a Diagnostic Trouble Code (DTC) related to fan control has been set, refer to the appropriate Powertrain Diagnostic Information for diagnostic procedures.