DTC P0116: Engine Coolant Temperature (ECT) Sensor 1 Range/Performance Problem: General Description

The engine control module (ECM)/powertrain control module (PCM) supplies voltage to the engine coolant temperature (ECT) signal circuit (about 5 V) through a pull-up resistor. As the engine coolant cools, ECT sensor 1 resistance increases, and the ECM/PCM detects a high signal voltage. As the engine coolant warms, ECT sensor 1 resistance decreases, and the ECM/PCM detects a low signal voltage. If the ECT sensor 1 output voltage does not reach a set temperature after starting the engine and driving a set time or when the difference between the ECT sensor 1 output voltage when driving and the output voltage of the ECT sensor 1 after the engine is stopped a set time does not change a certain amount, the ECM/PCM detects a malfunction and stores a DTC.