Chery T21 2014 Service Manual page 409

Knock Sensor
Description
The knock sensor is installed on cylinder block, and used to detect engine vibration caused by detonation.
Operation
The sensitive element of knock sensor is a piezoelectric ceramic. Vibration of engine cylinder block is
transferred to the piezoelectric ceramic through a mass block in knock sensor. Due to the pressure generated
by vibration of mass block, the piezoelectric ceramic generates a voltage at both electrode faces, and
converts the vibration signal to an AC voltage signal to output it. As intensity of vibration increases, knock
sensor output voltage increases accordingly.
Because frequency of vibration signal caused by engine knocking is far more than that of normal engine
vibration signal, Engine Control Module (ECM) can distinguish between knock or non-knock signals by
processing these signals from knock sensor.
Removal
1. Turn off all electrical equipment and ignition switch.
2. Disconnect negative battery cable.
3. Remove engine trim cover.
4. Remove knock sensor.
a. Disconnect knock sensor connector, and move away
the knock sensor cable from bracket.
b. Remove intake manifold assembly
c. Remove knock sensor fixing bolt and knock sensor.
(Tightening torque: 20 ± 5 N·m)
Chery Automobile Co., Ltd.
06 - SQR484F ENGINE MANAGEMENT SYSTEM
(See page 10-24).
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RT21060330
RT21060340
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