Nissan Maxima Service and Repair Manual: P0117, P0118 ECT sensor

Description

Nissan Maxima. Description

The engine coolant temperature sensor is used to detect the engine coolant temperature. The sensor modifies a voltage signal from the ECM. The modified signal returns to the ECM 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.

<Reference data>

Nissan Maxima. Reference data

Nissan Maxima. Reference data

*: These data are reference values and are measured between ECM terminals 46 (Engine coolant temperature sensor) and 52 (Sensor ground).

DTC Logic

DTC DETECTION LOGIC

Nissan Maxima. DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.

  1. Turn ignition switch OFF and wait at least 10 seconds.
  2. Turn ignition switch ON.
  3. Turn ignition switch OFF and wait at least 10 seconds.

2.PERFORM DTC CONFIRMATION PROCEDURE

  1. Turn ignition switch ON and wait at least 5 seconds.
  2. Check DTC.

Diagnosis Procedure

1.CHECK GROUND CONNECTION

  1. Turn ignition switch OFF.
  2. Check ground connection E9.

2.CHECK ECT SENSOR POWER SUPPLY CIRCUIT

Nissan Maxima. CHECK ECT SENSOR POWER SUPPLY CIRCUIT

  1. Disconnect engine coolant temperature (ECT) sensor harness connector.
  2. Turn ignition switch ON.
  3. Check the voltage between ECT sensor harness connector and ground.

Nissan Maxima. CHECK ECT SENSOR POWER SUPPLY CIRCUIT

3.CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

Nissan Maxima. CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT

  1. Turn ignition switch OFF.
  2. Disconnect ECM harness connector.
  3. Check the continuity between ECT sensor harness connector and ECM harness connector.
  4. Also check harness for short to ground and short to power.

4.CHECK ENGINE COOLANT TEMPERATURE SENSOR

5.CHECK INTERMITTENT INCIDENT

Component Inspection

1.CHECK ENGINE COOLANT TEMPERATURE SENSOR

Nissan Maxima. CHECK ENGINE COOLANT TEMPERATURE SENSOR

  1. Turn ignition switch OFF.
  2. Disconnect engine coolant temperature sensor harness connector.
  3. Remove engine coolant temperature sensor.
  4. Check resistance between engine coolant temperature sensor terminals as per the following.

Nissan Maxima. CHECK ENGINE COOLANT TEMPERATURE SENSOR

    P0116 ECT sensor

    P0122, P0123 TP sensor