Yaris 2007

Knock Sensor

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Location



Specific to:

Toyota Yaris 2007-2010

Refer to the accompanying illustration.

Click image to see an enlarged view

Fig. Locating the knock sensor

Operation



Specific to:

Toyota Yaris 2007-2010

The Knock Sensor (KS) is a piezo-electric (pressure-sensitive) electronic device that enables the Powertrain Control Module (PSM) to control the ignition timing for optimum performance, and to protect the engine from potentially damaging levels of detonation. The PCM uses the KS system to test for abnormal engine noise that may indicate detonation, which is also known as spark knock.

Removal & Installation



Specific to:

Toyota Yaris 2007-2010

  1. Disconnect the negative battery cable.
  2.  
  3. Drain and recycle the engine coolant.
  4.  
  5. Remove the engine cover.
  6.  
  7. Remove the air cleaner assembly.
  8.  
  9. Remove the throttle body.
  10.  
  11. Remove the intake manifold.
  12.  
  13. Disconnect the knock sensor connector.
  14.  
  15. Remove the nut and remove the knock sensor.
  16.  
  17. To install, reverse the removal procedure.
  18.  
  19. Tighten the knock sensor bolt to 15 ft. lbs. (20 Nm).
  20.  
  21. Make sure the connector is pointing downwards.

    Click image to see an enlarged view

    Fig. Remove the nut and remove the knock sensor

  22.  

Testing



Specific to:

Toyota Yaris 2007-2010


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

Knock Sensor Strategy

Specific to:

Toyota Yaris 2007-2010

The Knock Sensor (KS) system uses one or two broadband one-wire sensors. The Knock Sensor generates an AC voltage signal of varying amplitude and frequency based on the engine vibration. The amplitude and frequency are dependent upon the level of knock that the KS detects. The control module receives the KS signal through a signal circuit, and the KS ground is supplied by the engine block through the sensor housing.

Click image to see an enlarged view

Fig. Active Knock Sensor (KS) Pattern

Related Diagnostic Trouble Codes

Specific to:

Toyota Yaris 2007-2010



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Fig. Related Diagnostic Trouble Codes

 
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