Solstice 2006-2008, Sky 2007-2008



The Engine Control Module (ECM) supplies a 5 volt signal to the engine coolant temperature sensor through a resistor in the ECM and measures the voltage. The voltage will be high when the engine is cold, and low when the engine is hot. By measuring the voltage, the ECM calculates the engine coolant temperature. Engine coolant temperature affects most systems the ECM controls.