Fan Control

Description
The electric cooling fan is PWM driven by the ECM. The PWM signal duty cycle is dependent upon the temperature of the bottom hose coolant temperature sensor.

There are two diagnostic checks on the output signal from the ECM: -
1. An electrical check where the ignition is on and the fan is activated. A short to battery positive, short to ground or open circuit condition can be detected.
2. An electrical check where the ignition is on and the fan is not activated. A short to battery positive, short or open circuit condition can be detected.