Diesel Engine

Radiator fan operation is controlled 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 on the back of the fan shroud.

If the cooling fan is inoperative or a Diagnostic Trouble Code (DTC) related to fan control has been set, for diagnostic procedures. Refer to DTC INDEX .