Engine Coolant Temperature (ECT) Sensor

Engine coolant temperature sensor is located by left front branch of intake manifold (1990-1992 model year) or in front of thermostat housing (1993-Early 1995 model year). Engine coolant temperature sensor provides engine coolant temperature information to Engine Control Module (ECM). Upon receiving signal from sensor, ECM will lengthen, slightly, time that injectors are open, and reduce this time as injectors reach normal operating temperature.

The ECT sensor decreases its resistance as engine coolant temperature increases. The ECM applies a voltage signal to the ECT sensor. The ECM detects a small current when the engine coolant is at a low temperature and a larger current with a high temperature.