Cooling Fan Motor Description

The radiator fan system used in this vehicle uses a solid state relay (Pulse Width Module) that controls the speed of the radiator fan.

A 5 volt signal is supplied to the Pulse Width Module (PWM). The PCM provides a pulsed ground for the PWM. Depending on the amount of pulse on time, the PWM puts out a proportional voltage to the fan motor at the lower speed. For instance, if the on time is 30 percent, then the voltage to the fan motor would be 3.6 volts.