Aspen 2007, Durango 2006-2007



The sensor provides an input to the Electronic Control Module (ECM). As coolant temperature varies, the sensor resistance changes, resulting in a different input voltage to the ECM. When the engine is cold, the ECM will demand slightly richer air-fuel mixtures and higher idle speeds until normal operating temperatures are reached.

The engine coolant sensor input also determines operation of the low and high speed cooling fans.