Temperature Sensors

When the vehicle operator determines what temperature is desired, the automatic system uses multiple sensors to achieve and maintain the desired temperature. The heater and A/C control software receives an input of the inside air temperature from the inside air temperature sensor. The inside air temperature sensor is an internal component of the heater and A/C control.

The left air duct temperature sensor provides the heater and A/C control software with the temperature of the heat in the duct work. A 5-volt reference signal is sent from the heater and A/C control to the left air duct temperature sensor over the left outblow sensor circuit. A thermister inside the sensor varies the voltage. That varied voltage provides a signal to the software inside the heater and A/C control. The left air duct temperature sensor is grounded through the sensor ground circuit.

The right air duct temperature sensor provides the heater and A/C control software with the temperature of the heat in the duct work. A 5-volt reference signal is sent from the heater and A/C control to the right air duct temperature sensor over the right outblow sensor circuit. A thermister inside the sensor varies the voltage. That varied voltage provides a signal to the software inside the heater and A/C control. The right air duct temperature sensor is grounded through the sensor ground circuit.

The ambient air outside temperature sensor provides the heater and A/C control software with the temperature outside the vehicle and displays that temperature on the heater and A/C control. As temperature increases, resistance decreases. A 5-volt reference signal is sent from the heater and A/C control to the ambient air outside temperature sensor over the outside temperature sensor circuit. A thermister inside the sensor varies the voltage. That varied voltage provides a signal to the software inside the heater and A/C control.

The outside air temperature sensor is located in the front grill area under the front bumper of the vehicle. The heater and A/C control uses this sensor to receive information on ambient air temperature. With this information, the heater and A/C control will give the driver the outside air temperature on the digital display. If the outside temperature increases, the displayed temperature will not change until the vehicle's speed is above 32 km/h (20 mph) for approximately one and a half minutes or the vehicles speed is above 72 km/h (45 mph) for approximately one minute.

These delays help prevent false readings. If the displayed temperature goes down, the outside temperature display is updated immediately. If the vehicle has been turned off for more than three hours, the current outside temperature will be shown when the vehicle is started. If it has been turned off for less than three hours, the temperature will be recalled from the previous vehicle operation.