Toyota Celica, Corolla, ECHO & MR2 1999-05

Knock Sensor

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Operation





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Fig. Location of the knock sensor

The knock sensor is fitted into the cylinder block to detect engine knocking. This sensor contains a piezoelectric element which generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If the engine knocking occurs, ignition timing is retarded to suppress it.

Removal & Installation



  1. Disconnect the wiring from the knock sensor.
  2.  
  3. Using tool, 09816-30010 or an equivalent socket, remove the knock sensor from the vehicle.
  4.  



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Fig. Place a special socket over the knock sensor and remove the sensor

  1. Inspect the vacuum hose over its entire length for any signs of cracking or splitting. The slightest leak can cause improper operation.
  2.  

To install:

  1. Install the knock sensor with the special tool, tighten securely to 33 ft. lbs. (44 Nm).
  2.  
  3. Connect the sensor wiring. Inspect the vacuum hose over its entire length for any signs of cracking or splitting. The slightest leak can cause improper operation.
  4.  

Testing



  1. Disconnect the wiring from the knock sensor.
  2.  
  3. Using tool 09816-30010 or an equivalent socket, remove the knock sensor from the vehicle.
  4.  
  5. Using an ohmmeter, check that there is no continuity between the terminal and the body.
  6.  
  7. If there is continuity, replace the sensor.
  8.  



Click image to see an enlarged view

Fig. Testing the knock sensor for continuity with an ohmmeter

  1. Install the knock sensor with the special tool, tighten securely to 33 ft. lbs. (44 Nm).
  2.  
  3. Connect the sensor wiring.
  4.  

 
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