Radiator Cooling Fan: Description and Operation

Radiator Fan Control Inputs And Outputs:

PURPOSE
The Radiator Fan Control System allows the Engine Control Module (ECM) to have precise control over the speed at which the radiator fan(s) operate.

Radiator Fan Control Operation:

OPERATION
The ECM will take inputs from the A/C switch on the dash, Vehicle Speed Sensor and the Engine Coolant Temperature Sensor to determine whether the radiator fan should be off, low speed or high speed. Refer to the operational tables below for more information.

Radiator fan speed is controlled by the ECM grounding one of three radiator fan relays.