Coolant Temperature Sensor

Coolant temperature sensor is located in upper radiator hose inlet housing. Sensor is a thermistor type which provides ECU with engine temperature information. ECU uses this information in determining control of air/fuel mixture, ignition timing, idle speed and exhaust gas recirculation and canister purge systems.

To determine engine temperature, ECU supplies and monitors a voltage signal to the coolant sensor. As engine temperature increases, sensor internal resistance decreases, causing ECU monitored voltage to decrease as more of the signal voltage passes through the sensor to ground.