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:
Low Tire Pressure
• This warning message illuminates
if the tire pressure is low with the
Engine Start/Stop button in ON
position.
Low Washer Fluid
This warning message illuminates
on the service reminder mode if
the washer fluid level in the reservoir
is nearly empty.
I ...
Removal and Installation
[Air Cleaner Assembly]
1.
Disconnect the battery "-" terminal from the trunk room.
2.
Remove the engine cover.
(Refer to Engine And Transaxle Assembly - "Engine Cover")
3.
Remove the engine room cover.
(Refer to Engine And Transaxle Assembly - "Engine Cover")
...