Knocking is a phenomenon characterized by undesirable
vibration and noise and can cause engine damage. The two Knock Sensors
(KS) are installed inside the V-valley of the cylinder block and sense
engine knocking.
When knocking occurs, the vibration from the cylinder block is applied as pressure to the piezoelectric element.
When knocking occurs, the sensor produces voltage signal and
the ECM retards the ignition timing. If the knocking disappears after
retarding the ignition timing, the ECM will advance the ignition timing.
This sequential control can improve engine power, torque and fuel
economy.

Other information:
Removal
1.
Disconnect the negative (-) battery terminal.
2.
Open the trunk, remove the left trunk trim.
(Refer to Body - "Trunk Trim")
3.
Remove the external amplifier (C) after disconnecting the connector (A),(B) and loosening the mounting nuts.
Installation
1.
Install the externa ...
Removal
•
Removal of the airbag must be performed according to the precautions/procedures described previously.
•
Before disconnecting the side impact sensor connector(s), disconnect the side airbag connector(s).
•
Do not turn the ignition switch ON and ...