Diesel Data: Automotive Repair

Radiator Cooling Fan Temperature Sensor / Switch: Description and Operation

California Only

Radiator Fan Motor Circuit:





PURPOSE
Radiator fan operation is monitored by the ECM, to determine the load on the engine under idle conditions.

OPERATION
The ECM monitors the voltage from the radiator fan motor relay. If system voltage is not present, (fan operating) The ECM operates the IAC motor to maintain correct idle RPM.