Control Module HVAC: Description and Operation

The A/C blower motor speed control is a Pulse Width Modulated (PWM) type which provides variable speed control of the A/C blower motor speed control. The EATC climate control assembly controls the blower motor speed by switching the control signal voltage on and off many times per second. By varying the ratio of time on (4.6 volts) to time off (0 volts), the EATC climate control assembly controls the blower motor speed to achieve the preferred or target temperature.