Theory Of Operation

The Radiator Fan Module is a smart device which is integrated into the Radiator Fan Assembly and receives the Pulse-Width Modulated (PWM) Radiator Fan speed signal from the Powertrain Control Module (PCM) to control fan speed. The Radiator Fan Module will control the fan speed based on this input. The Radiator Fan Module performs diagnostics on the Radiator Fan circuits. If a fault is detected in the voltage supply, ground or internal fan circuitry, the Radiator Fan Module sends a fault message to the PCM using the same PWM circuit. During normal operation, the Radiator Fan can be operated between 10% duty cycle (Low speed) and 92% duty cycle (High speed).