GMC Engine Coolant Temperature (ECT) Sensor Replacing?

Coolant Temperature Sensor monitors the temperature of the engine and sends that information to the engine control computer to regulate the amount of fuel needed. More fuel is needed if the engine is cold; less if it's hot. If the temperature is extreme, the signal will be sent to the temperature gauge as a visual indicator of overheating and imminent danger.

The sensor replacing details is as follows :---

OPERATION

The Engine Coolant Temperature (ECT) sensor is mounted in the intake manifold and sends engine temperature information to the VCM. The VCM supplies 5 volts to the coolant temperature sensor circuit. The sensor is a thermistor which changes internal resistance as temperature changes. When the sensor is cold (internal resistance high), the VCM monitors a high signal voltage which it interprets as a cold engine. As the sensor warms (internal resistance low), the VCM monitors a low signal voltage which it interprets as warm engine.

TESTING

See Figures 1, 2 and 3

1. Remove the ECT sensor from the vehicle.
2. Immerse the tip of the sensor in container of water.
3. Connect a digital ohmmeter to the two terminals of the sensor.
4. Using a calibrated thermometer, compare the resistance of the sensor to the temperature of the water. Refer to the engine coolant sensor temperature vs. resistance illustration.
5. Repeat the test at two other temperature points, heating or cooling the water as necessary.
6. If the sensor does not met specification shown in the temperature versus resistance chart, it must be replaced.
7. The sensor may also be checked in the vehicle. Unplug the sensor and attach a digital ohmmeter to the two terminals of the sensor.
8. Using a calibrated thermometer, compare the resistance of the sensor to the ambient air temperature.
9. Repeat the test at two other temperature points, heating or cooling the water as necessary.
10. If the sensor does not met specification shown in the temperature versus resistance chart, it must be replaced.

Fig. Fig. 1: Testing the Engine Coolant Temperature (ECT) sensor resistance

Fig. Fig. 2: Engine Coolant Temperature (ECT) sensor wiring diagram (wire color, terminal identification/location may vary on certain models)

Fig. Fig. 3: Engine Coolant Temperature (ECT) sensor temperature vs. resistance values

REMOVAL & INSTALLATION

See Figures 4 through 9

Fig. Fig. 4: Engine Coolant Temperature (ECT) sensor location-1994-95 4.3L TBI engines

Fig. Fig. 5: Engine Coolant Temperature (ECT) sensor location-1994-95 4.3L CMFI engines

Fig. Fig. 6: Engine Coolant Temperature (ECT) sensor location-1996- 1997 4.3L engines

Fig. Fig. 7: Engine Coolant Temperature (ECT) sensor location-1994-97 2.2L engines

Fig. Fig. 8: Engine Coolant Temperature (ECT) sensor location-1998-99 2.2L engines

Fig. Fig. 9: Engine Coolant Temperature (ECT) sensor location-1998-99 4.3L engines

1. Disconnect the negative battery cable.
2. Drain the cooling system below the level of the sensor and unplug the sensor electrical connection.
3. Remove the coolant sensor.

To install:

4. On 1998-99 models, coat the threads of the sensor with a suitable water resistant sealer such a sealer 9985253 or its equivalent.
5. Install the sensor and engage the electrical connector.
6. Refill the cooling system and connect the negative battery cable.

---------------

This details will help you.Thanks.

------------

See list of related help solutions:----

MAF, IAT, MAP and Coolant Level Sensor problem all together on Mazda MPV?

http://schematicsdiagram.blogspot.com/2011/12/maf-iat-map-and-coolant-level-sensor.html

Coolant Level Sensor on Audi A4?

http://repairhelpcenter.blogspot.com/2011/11/coolant-level-sensor-on-audi-a4.html

For details regarding:--

How does Vehicles Engine cooling system works?

http://repairhelpcenter.blogspot.com/2011/11/how-does-vehicles-engine-cooling-system.html

Engine cooling components working?

http://repairhelpcenter.blogspot.com/2011/11/engine-cooling-components-working.html