Circuit Description
WARNING: This page is about a different car, the 2002 Oldsmobile Intrigue. However, it is still accessible from the selected car via links, so may be relevant.
The HVAC control module monitors the inside air temperature through a inside air temperature sensor. The inside air temperature sensor is a variable resistor. The HVAC control module supplies 5 volts to the inside air temperature sensor signal circuit and provides a low reference circuit. When the air is cold, the sensor resistance and signal voltage are high. When the air is warm, the sensor resistance and signal voltage are low. The HVAC control module requests A/C compressor clutch engagement and controls the air temperature actuator door positions in order to maintain the selected air temperature.