DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control: General Description

The Engine Coolant Temperature (ECT) sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the Powertrain Control Module (PCM). The modified signal returns to the PCM as the engine coolant temperature input. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.