Diesel Engine
WARNING: This page is about a different car, the 2012 Jeep Patriot and 2012 Jeep Compass. However, it is still accessible from the selected car via links, so may be relevant.
Radiator fan operation is controlled by the Engine Control Module (ECM) 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 ECM turns on the fan through either the high or low speed fan relay. The ECM 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 appropriate diagnostic information .