P0118 - ENGINE COOLANT TEMPERATURE SENSOR CIRCUIT HIGH INPUT

P0118

Description of DTC code P0118

The ECT is located in the coolant duct. Its resistance changes in accordance with the coolant temperature. For example, when is low temperature, the resistance of the sensor is high, and when the temperature rises, the resistance decreases. In addition, the Power Train Control Module (PCM) provides 5 volts of reference, plus a ground to the Engine Coolant Temperature (ECT) sensor.

To determine the coolant temperature, the Powertrain Control Module (PCM) monitors the voltage drop. In case the Engine Coolant Temperature sensor gives a reading lower than the freezing temperature, and the motor has more than 2 minutes of operation, the PCM concludes that may have a fault in the circuit and the DTC code P0118 OBD2 is established. Also, this code is established if the PCM determines that the resistance of the ECT sensor is not within the specifications.

Symptoms of fault code P0118

  • Check Engine light turns on.
  • There may be difficulties when starting the vehicle.
  • Black smoke comes out of the exhaust.
  • Poor fuel economy.

Causes of OBD2 P0118

The reasons why the fault code P0118 OBDII can be established can be:

  • The supply voltage of the Engine Coolant Temperature Sensor (ECT) may be short.
  • The earth circuit between the Engine Coolant Temperature (ECT) sensor and the Powertrain Control Module (PCM) may be short-circuited.
  • Bad electrical connection in the ECT sensor.
  • Possibly the ECT sensor could be defective.

Possible solutions of the DTC code P0118

Before the diagnostic code P0118 OBD2 you can do the following for its correct repair:

  • Inspect the cables and connectors that lead to the ECT sensor. They can have wear or corrosion. Repair or change as necessary.
  • With a scan tool, check the reading of the Engine Coolant Temperature Sensor (ECT). After analyzing, compare the results with the specifications. If it is not inside them, proceed to replace the ECT sensor.
  • If it is within specifications, disconnect the sensor. Then you must make a bridge between the two terminals of the connector. The reading obtained must exceed 250 ° F. If not, it indicates that there is a problem in the voltage supply or in the ground circuit.
  • Verify that the 5 volts of reference are present. Also there is continuity to ground, in addition to having return to the PCM connector. If they are present in the PCM connector, it means that there is a short circuit between the PCM and the ECT sensor. Repair it.
  • Change the Engine Coolant Temperature (ECT) sensor.

Codes related to P0118

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