Ambient Air Temperature

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.

The ambient air temperature is read by the instrument panel cluster (IPC) and displayed in the driver information center (DIC). The IPC provides the logic for reading the outside air temperature sensor. The IPC is responsible for displaying the temperature and converting to Fahrenheit. The instrument panel cluster (IPC) applies 5 volts to the ambient air temperature sensor. The ambient air temperature sensor is a thermistor which varies in resistance as the temperature changes. As the resistance of the ambient air temperature sensor increases, the IPC senses a larger voltage drop across the sensor, indicating a lower temperature. As the resistance of the ambient air temperature sensor decreases, the IPC senses a smaller voltage drop across the sensor, indicating a higher temperature. The IPC is responsible for displaying the temperature and converting to degrees Fahrenheit if necessary.

If the ambient air temperature sensor resistance is less than 328 ohms, the IPC displays 'SC' (short circuit) in the DIC and this corresponds to a temperature of 125°C (257°F). If the ambient air temperature sensor resistance is greater than 353.37K ohms, the IPC displays 'OC' (open circuit) in the DIC and this corresponds to a temperature less than -40°C (-40°F). The IPC displays ' - - ' in the DIC when the IPC receives an invalid signal or a loss of serial data communication.