Idle Speed Control

Engine Coolant Temperature (ECT) Sensor The engine coolant temperature (ECT) sensor is located on the coolant outlet elbow. It is a temperature dependent resistor (thermistor), the voltage output of which varies in inverse proportion to temperature, in that the output increases as temperature decreases or the reverse. The change in resistance is monitored by the ECM on the K/G wire and as a result the ECM can adjust the length of injector opening time required. The ECM supplies the coolant temperature sensor with an earth path on the K/B wire.

Idle Speed Control

When the throttle position sensor signal indicates throttle closed position and the engine is at idle, the ECM implements an idle ignition setting.

NOTE: Due to the sensitivity of this system the ignition timing at idle is continually changing.