Sienna 1998-1999

Knock Sensor

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Operation



Specific to:

Toyota Sienna 1998-2005

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 Sienna 1998-2005

  1. Before servicing the vehicle, refer to the precautions.
  2.  
  3. Disconnect the negative battery cable.
  4.  
  5. Remove the intake manifold.
  6.  
  7. Disconnect the wiring harness.
  8.  
  9. Unbolt and remove the knock sensors.
  10.  

To install:

  1. Installation is the reverse of removal.
  2.  
  3. Tighten the knock sensor bolts to 15 ft. lbs.(20 Nm).
  4.  

Testing



Specific to:

Toyota Sienna 1998-2005


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

Knock Sensor Strategy

Specific to:

Toyota Sienna 1998-2005

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 Sienna 1998-2005



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
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