Engine Coolant Temperature Sensor (ECTS)

ECTS is located on top of thermostat housing. Sensor is a thermistor type, which provides ECM with engine temperature information. ECM uses this information to control air/fuel mixture, ignition timing, idle speed, exhaust gas recirculation system and canister purge system. This input is also used in calculating ECM control of variable valve timing.

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