For 1990-2009 cars

The ambient temperature sensor (1) is a temperature-sensitive resistor. The ambient temperature sensor's resistance varies inversely with the temperature. As the outside air temperature increases, the resistance decreases. As outside air temperature decreases, the resistance increases.

The heater and A/C programmer performs the following functions:

• | Monitors the outside temperature signal.

• | Uses the outside temperature information in order to display the outside temperature on the heater and A/C control vacuum fluorescent (VF) display.

• | Helps determine the command signals.