Theory Of Operation

The pulse-width modulated (PWM) fan receives a duty cycle signal from the Totally Integrated Power Module (TIPM) on the (K175) Rad Fan High Speed Control circuit. Based on the requested fan speed from the PCM, the TIPM outputs a 10 Hz duty cycle signal on the (K175) Rad Fan High Speed Control circuit to the Radiator Cooling Fan. The Radiator Cooling Fan receives the duty cycle signal from the TIPM and controls the fan accordingly. The High Speed Cooling Fan Relay is not used to control any components and has no external function.