Knocking is a phenomenon characterized by undesirable
vibration and noise and can cause engine damage. The two Knock Sensor
(KS) are installed inside the V-valley of the cylinder block and senses
engine knocking.
When knocking occurs, the vibration from the cylinder block is applied as pressure to the piezoelectric element.
When a knock occurs, the sensor produces voltage signal. The
ECM retards the ignition timing when knocking occurs. 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.
Inspection
1.
Check the signal waveform of the CMPS and CKPS using the GDS.
Specification: Refer to “Wave Form”
Removal
•
DON''T remove the camshaft position sensor while the engine
is running or right after engine is turned off.
Troubleshooting
Examples of False-Alarm Occurrence from system characteristics (It’s not a problem)
–
Characteristics of EM Wave : EM Waves are reflected against
all material and especially metal very well. Reflections of EM Waves are
varies with the shape of object.