Circuit/System Description

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The instrument panel cluster (IPC) monitors the ambient air temperature sensor to display ambient air temperature. The temperature sensor is a 2-wire negative temperature co-efficient thermistor. The IPC applies 5 volts to an internal input resistor that is connected to the signal circuits of the ambient air temperature sensor. The IPC provides the ground to the ambient air temperature sensor through the low reference circuit. The IPC monitors the voltage drop across the ambient air temperature sensor and uses the input for automatic control calculations. When the ambient air temperatures are cold, the resistance of the sensor is high and the voltage signals are high. When the ambient air temperatures are hot, the resistance of the sensors is low and the voltage signals are low. The IPC converts the voltage value to a temperature value of Celsius and Fahrenheit that will be displayed by the IPC.