Air Outlet Temperature Sensor - Operation

OPERATION

The air duct temperature sensors monitor the temperature of the conditioned air leaving the HVAC housing and supplies an input signal to the A/C heater control, when equipped with the Automatic Temperature Control (ATC) heating and A/C system. The air duct temperature sensors change their internal resistance in response to the temperatures they monitor. The air duct temperature sensors are connected to the ATC A/C heater control through a sensor ground circuit and a 5 volt Direct Current (DC) reference signal circuit. As the temperature of the conditioned air leaving the HVAC housing decreases, the internal resistance of the temperature sensor increases. As the temperature of the conditioned air leaving the HVAC housing increases, the internal resistance of the temperature sensor decreases.

The ATC A/C heater control uses the monitored voltage readings as an indication of air outlet temperature. The A/C heater control is programmed to respond to this and other inputs by adjusting the blend and the mode air door positions, and by cycling the A/C clutch on and off as necessary in order to automatically adjust the heating and A/C system to the operator temperature preference setting.

The air duct temperature sensors are diagnosed using a scan tool A L L Diagnostic Trouble Codes ( DTC ).

The air duct temperature sensors cannot be adjusted or repaired and must be replaced if inoperative or damaged.