P0116 - ECT SENSOR CIRCUIT RANGE/PERFORMANCE

The Engine Coolant Temperature (ECT) is a sensor used to detect the temperature level in the coolant. This ECT changes a voltage signal from the Engine Control Module (ECM), then forwards that signal to the ECM, which interprets it as the engine coolant temperature input.

The ECT sensor uses a thermistor, which reacts to the change in temperature. When the temperature rises the resistance falls and when the temperature falls the resistance increases.

The Engine Control Module (ECM) observes slow changes in the resistance of the ECT sensor signal circuit. If you see a rapid change in voltage that does not match the engine temperature or see a lack of change in the ECT signal, the diagnostic code P0116 OBDII is set.

• Illuminated MIL light (Check Engine).
• Black smoke from the exhaust.
• It lowers fuel efficiency.
• Driving the engine could be faulty.

The reasons for the DTC code P0116 OBD2 are

• The thermostat may be stuck.
• Problems with the signal or ground wire, causing a short in the circuit.
• Poor wiring connections.
• The Coolant Temperature Sensor (ECT) is probably defective.

To solve the problems caused by the fault code P0116 OBDII, you must do the following:

• If there are other codes related to the ECT sensor, solve them.
• By using an automotive scanning tool, check the reading of the Engine Coolant Temperature (ECT). Note that when the engine is cold, the ECT sensor reading must be equal to the ambient temperature.
• Look for faulty wires in the signal circuit and the coolant temperature sensor ground circuit. If you find features such as wear or corrosion on one of these components, make the necessary repair or replace it.