P1116 - FAULT CODE - OBD2

P1116 ACURA, HONDA: ENGINE COOLANT TEMPERATURE SENSOR PERFORMANCE ISSUE

P1116 CADILLAC, BUICK, CHEVROLET, GMC: ENGINE COOLANT TEMPERATURE SENSOR SIGNAL UNSTABLE OR INTERMITTENT

P1116 FORD, LINCOLN, MAZDA, MERCURY: ENGINE COOLANT TEMPERATURE SENSOR OUT OF SELF-TEST RANGE

The Engine Coolant Temperature Sensor (ECT) is an electronic device that receives a reference and ground signal through 2 wires. Being a negative coefficient, the resistance of this sensor changes according to the temperature. That is, if the resistance is low, it is because the temperature increases. When resistance variations occur, it is because the sensor voltage has changed, and it is not recognized by the PCM (Powertrain Control Module) as ECT changes. This sensor is usually located in the engine coolant hoses.

The P1116 OBDII fault code is a manufacturer-specific code, which indicates an ECT sensor voltage problem. When this code is set, it is because the PCM has detected that the voltage sent by this sensor it is not within the established range. So, it is not possible to accurately transmit the engine coolant temperature readings.

• Check Engine lamp illuminates.
• The temperature gauge does not work.
• Engine coolant temperature turns out to be low or excessively high.

The reasons for storing the P1116 OBD2 diagnostic code are:

• Engine coolant level may not be enough.
• The ECT sensor circuit may have damage to its wiring.
• Probably, there is a short or open circuit in the Engine Coolant Temperature Sensor.
• The ECT Sensor may be faulty.
• Engine coolant thermostat may be faulty.
• The PCM may be damaged.

To troubleshoot the DTC P1116 OBDII code, try this:

• Consult the TSBs (Technical Service Bulletins).
• Check that the engine coolant level is required for the proper system operation. Verify there are no leaks or other damage to the coolant reservoir.
• Inspect and check the condition of the wires that are connected to the engine coolant temperature sensor circuit. If you notice they are damaged by burning, wear, or corrosion, make repairs.
• Verify that the ECT Sensor circuit meets the voltage requirements for good performance. Compare the readings you obtain with those specified by the manufacturer. If you find differences, make the necessary repairs.
• By using a multimeter, check the ECT Sensor voltages. If these voltages do not match those indicated on the data source, replace it.