Toyota Coolant Temperature Sensor Operation,Testing & Replacing?

Coolant Temperature Sensor
Operation
Removal & Installation
Testing

The details are for Toyota Celica, Corolla, ECHO & MR2 Car models.

The procedure is for Above Mentioned car Engine models:----

1ZZ-FE VIN R
2ZZ-FE VIN Y
5S-FE VIN G

Coolant Temperature Sensor:---

1. Drain engine coolant.
2. Disconnect the ECT sensor connector.
3. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.
4. Using an ohmmeter, measure the resistance between terminals 1 and 2.
5. If the resistance is not as specified, replace the ECT sensor. 
   
   
   
   Fig. ECT testing

To install:

1. Install a new gasket to the ECT sensor.
2. Using a 19 mm deep socket, install the ECT sensor. Tighten to 14 ft. lbs. (20 Nm).
3. Connect the ECT sensor connector.
4. Refill with engine coolant.

Removal & Installation Procedure for Coolant temperature sensor:---

1. Disconnect the air/fuel ratio sensor connector.
2. Remove the four bolts that retains the exhaust manifold heat insulator. 
   
   
   
   Fig. Removal of the exhaust manifold
3. Remove the five nuts and then the exhaust manifold
4. To prevent possible damage, remove the gasket from the cylinder head. 
   
   
   
   Fig. Removal of the Engine Coolant Temperature (ECT) Sensor
5. Using Special Tool 09817-33190, remove the Engine Coolant Temperature Sensor.

To install:

1. Using Special Tool 09817-33190, replace the Engine Coolant Temperature Sensor.
2. Replace the cylinder head gasket.
3. Replace the exhaust manifold and the five retaining nuts.
4. Replace the exhaust manifold heat insulator and the four bolts.
5. Connect the air/fuel ratio sensor connector.

Operation:---

The Engine Coolant Temperature (ECT) sensor's function is to advise the ECM of changes in engine temperature by monitoring the changes in coolant temperature. The sensor must be handled carefully during removal. It can be damaged (thereby affecting engine performance) by impact.

Testing Coolant Temperature Sensor:---

1ZZ-FE VIN R

2ZZ-FE VIN Y

5S-FE VIN G

1. Disconnect the engine wiring harness from the ECT sensor.
2. Connect an ohmmeter between the ECT sensor terminals.

Fig. Inspect the resistance between the terminals of the engine coolant temperature sensor

1. With the engine cold and the ignition switch in the OFF position, measure and note the ECT sensor resistance.
2. Connect the engine wiring harness to the sensor.
3. Start the engine and allow the engine to reach normal operating temperature.
4. Once the engine has reached normal operating temperature, turn the engineOFF .
5. Once again, disconnect the engine wiring harness from the ECT sensor.
6. Measure and note the ECT sensor resistance with the engine hot.
7. Compare the cold and hot ECT sensor resistance measurements with the accompanying chart.

Fig. Submerge the sensor in water and check the testing with the Engine Coolant Temperature (ECT) sensor chart

1. If readings do not approximate those in the chart, the sensor may be faulty.

1. Drain engine coolant.
2. Disconnect the ECT sensor connector.
3. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.
4. Using an ohmmeter, measure the resistance between the terminal. The results should be between 2.32 to 2.59 kohms at 68 degrees F.
5. If checking the engine coolant temperature sensor in water, be careful not to allow water to intrude into the terminals. After checking, wipe up water on the engine coolant temperature sensor. If the result is not as specified, replace the engine coolant temperature sensor.

1ZZ-FE VIN R

1. Drain engine coolant.
2. Disconnect the ECT sensor connector.
3. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.
4. Using an ohmmeter, measure the resistance between terminals 1 and 2.
5. If the resistance is not as specified, replace the ECT sensor. 
   
   
   
   Fig. ECT testing

To install:

1. Install a new gasket to the ECT sensor.
2. Using a 19 mm deep socket, install the ECT sensor. Tighten to 14 ft. lbs. (20 Nm).
3. Connect the ECT sensor connector.
4. Refill with engine coolant.

2ZZ-FE VIN Y

1. Drain engine coolant.
2. Disconnect the ECT sensor connector.
3. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.
4. Using an ohmmeter, measure the resistance between terminals 1 and 2.
5. If the resistance is not as specified, replace the ECT sensor. 
   
   
   
   Fig. ECT testing

To install:

1. Install a new gasket to the ECT sensor.
2. Using a 19 mm deep socket, install the ECT sensor. Tighten to 14 ft. lbs. (20 Nm).
3. Connect the ECT sensor connector.
4. Refill with engine coolant.

5S-FE VIN G

1. Drain engine coolant.
2. Disconnect the ECT sensor connector.
3. Using a 19 mm deep socket wrench, remove the ECT sensor and gasket.
4. Using an ohmmeter, measure the resistance between terminals 1 and 2.
5. If the resistance is not as specified, replace the ECT sensor. 
   
   
   
   Fig. ECT testing

These details will help.

Thanks.

FOR MORE HELP GO TO: ---

Car repair guide?

http://technoanswers.blogspot.in/2012/03/car-repair-guide.html