Circuit/System Description

WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.

The HVAC control module supplies the evaporator temperature sensor with a low reference circuit and 5-volt signal circuit. The HVAC control module determines the voltage drop across the sensor, which is proportional to temperature. When the refrigerant temperature is low the sensor resistance and voltage signal are high. When the refrigerant temperature is high the sensor resistance and voltage signal are low. The sensor works in conjunction with a switch to meter the flow of refrigerant therefore preventing the freezing of moisture that condenses on the evaporator. An evaporator with little refrigerant will starve causing insufficient cooling. An evaporator flooded with refrigerant will also cause poor cooling when there is too much liquid refrigerant that cannot vaporize quickly.