Camry 2008-2009

Engine Coolant Temperature Sensor

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Location



Specific to:

Toyota Camry 2009-2010

The ECT sensor is connected to the air cleaner case sub assembly.

Click image to see an enlarged view

Fig. Engine Coolant Temperature (ECT) sensor-Hybrid engine

Operation



Specific to:

Toyota Camry 2007-2008

A thermistor is built into the engine coolant temperature sensor, of which the resistance value varies according to the engine coolant temperature. The structure of the sensor and its connection to the ECM are the same as those of the intake air temperature sensor.

Specific to:

Toyota Camry 2009-2010

The Engine Coolant Temperature (ECT) Sensor is a Negative Temperature Coefficient (NTC) Thermistor that monitors the engine coolant temperature. The ECT Sensor operates within a 5 volt DC reference range, and provides a linear input signal to the Powertrain Control Module (PCM) that is based upon the measured engine coolant temperature. The PCM uses data from the ECT Sensor to calculate air-fuel mixture, ignition timing, and fuel injector pulse width. In some instances, the ECT signal is used to control the engine cooling fans and the operation of the air conditioning (A/C) system.

Removal & Installation



2.4L Engine

Specific to:

Toyota Camry 2007-2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Drain and recycle the engine coolant.
  6.  
  7. Remove the plastic engine cover.
  8.  
  9. Remove the air cleaner inlet assembly.
  10.  
  11. Remove the air cleaner cap sub-assembly.
  12.  
  13. Remove the air cleaner case sub-assembly.
  14.  
  15. Disconnect the ECT sensor connector.
  16.  
  17. Using Special Tool: 09817-33190, remove the engine coolant temperature sensor and gasket.

    Click image to see an enlarged view

    Fig. Removing the ECT sensor-2.4L Engine

  18.  

To install:

  1. Installation is the reverse of the removal procedure. Torque the engine coolant temperature sensor to 15 ft. lbs. (20 Nm).
  2.  
  3. Add coolant and check for leaks.
  4.  

Specific to:

Toyota Camry 2009-2010

  1. Drain the engine coolant.
  2.  
  3. Remove the No. 1 engine cover sub assembly.
  4.  
  5. Remove the air cleaner inlet assembly.
  6.  
  7. Remove the air cleaner cap sub assembly.
  8.  
  9. Remove the air cleaner case sub assembly.
  10.  
  11. Remove the Engine Coolant Temperature (ECT) sensor.
    1. Disconnect the ECT sensor connector.
    2.  
    3. Using the SST (09817-33190), remove the ECT sensor and gasket.

      Click image to see an enlarged view

      Fig. Removing the ECT sensor-2.4L non-hybrid engine



      Click image to see an enlarged view

      Fig. Removing the ECT sensor-2.4L hybrid engine

    4.  

  12.  

To install:

  1. Install the ECT sensor.
    1. Install a new gasket onto the ECT.
    2.  
    3. Using the SST (09817-33190), install the ECT. Tighten to 15 ft. lbs. (20 Nm).
    4.  

  2.  
  3. Install the air cleaner case sub assembly.
  4.  
  5. Install the air cleaner cap sub assembly.
  6.  
  7. Install the air cleaner inlet assembly.
  8.  
  9. Add engine coolant.
  10.  
  11. Inspect for coolant leaks.
  12.  
  13. Install the No. 1 engine cover sub assembly.
  14.  

3.5L Engine

Specific to:

Toyota Camry 2007-2008

  1. Before servicing the vehicle, refer to the Precautions Section.
  2.  
  3. Drain engine coolant.
  4.  
  5. Remove V-bank cover sub-assembly.
  6.  
  7. Remove the air cleaner inlet assembly.
  8.  
  9. Remove the air cleaner cap sub-assembly.
  10.  
  11. Remove the air cleaner case sub-assembly.
  12.  
  13. Remove No. 1 air cleaner inlet.
  14.  
  15. Remove the engine coolant temperature sensor connector.
  16.  
  17. Using a19 mm deep socket wrench, remove the engine coolant temperature sensor and gasket.

    Click image to see an enlarged view

    Fig. Removing the ECT sensor-3.5L Engine

  18.  

To install:

  1. Installation is the reverse of the removal procedure. Torque the engine coolant temperature sensor to 15 ft. lbs. (20 Nm).
  2.  

Specific to:

Toyota Camry 2009-2010

  1. Remove the engine under covers.
  2.  
  3. Drain the engine coolant.
  4.  
  5. Remove the v-bank cover sub assembly.
  6.  
  7. Remove the air cleaner inlet assembly.
  8.  
  9. Remove the air cleaner cap sub assembly.
  10.  
  11. Remove the air cleaner case sub assembly.
  12.  
  13. Remove the No. 1 air cleaner inlet.
  14.  
  15. Remove the Engine Coolant Temperature (ECT) sensor.
    1. Remove the ECT sensor connector.
    2.  
    3. Remove the engine coolant temperature sensor.

      Click image to see an enlarged view

      Fig. Removing the ECT sensor-3.5L engine

    4.  

  16.  

To install:

To install, reverse the removal procedure. Tighten the ECT sensor to 15 ft. lbs. (20 Nm).

Testing



Specific to:

Toyota Camry 2007-2008

  1. Using an ohmmeter, measure the resistance between the terminals:
    1. Condition:


    2.  
    3. 68°F (20°C) at 2.32 to 2.59 kilo ohms.
    4.  
    5. 176°F (80°C) at 0.310 to 0.326 kilo ohms.
    6.  

  2.  
  3. If the resistance is not as specified, replace the ECT sensor.
    NOTE
    When checking the engine coolant temperature sensor in water, do not allow water to go into the terminals. After checking, dry the sensor.



    Click image to see an enlarged view

    Fig. Coolant temperature sensor resistance

  4.  

Connection & Wiring Diagnosis

Specific to:

Toyota Camry 2009-2010

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

ECT Circuit Testing

Specific to:

Toyota Camry 2009-2010

Use a suitable scan tool, a Graphing Multi-Meter (GMM), or a Digital Volt-Ohm Meter (DVOM) in order to view the ECT data.

ECT Sensor logic is relative to the scale of resistance: when the coolant temperature is low, the voltage is increased. When the coolant temperature is high, the voltage is decreased.

Use a suitable pyrometer or thermometer, as well as visual observation to verify that the cooling system is operating properly. If a cooling system fault is evident, repair as required before continuing.

If a DVOM is being used, additional information may be acquired by taking measurements at the sensor connector as well as the PCM connector. If a significant voltage drop is measured (greater than 0.5 volts DC), check the wiring harness and connections for corrosion, poor pin connections, or damaged wires.

If all engine wiring and pin connections are confirmed, disconnect the ECT Sensor to verify the signal with a DVOM, and verify PCM communication before replacing the ECT Sensor.

Click image to see an enlarged view

Fig. ECT Sensor Range Chart

ECT Sensor Strategy

Specific to:

Toyota Camry 2009-2010

The ECT Sensor provides a linear input signal to the Powertrain Control Module (PCM) for a number of engine control system calculations. The ECT signal is compared with Manifold Absolute Pressure (MAP), Mass Air Flow (MAF), Intake Air Temperature (IAT), and Fuel Trim (HO2S) in order to determine the correct air-fuel mixture for measured operating conditions. In some cases the ECT Sensor input is used in concert with the A/C Pressure (ACP) Sensor input in order to determine cooling fan and A/C system operation.

Related Diagnostic Trouble Codes

Specific to:

Toyota Camry 2009-2010



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
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