Kia Carens: Engine Control System / Knock Sensor (KS) Description and operation
Knocking is a phenomenon characterized by undesirable vibration and noise and
can cause engine damage. Knock Sensor (KS) is installed on 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”
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Specification
Item
Specification
Capacitance (pF)
950 ~ 1,350
Resistance (MΩ)
4.87
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Other information:
Removal and Installation
1.
Remove the drive belt.
(Refer to Timing System - "Dreve Belt")
2.
Remove the alternator.
(Refer to Engine Electrical System - "Alternator")
3.
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Troubleshooting
Symptom
Suspect area
Engine will not start or struggle to start
Vapor hose damaged or disconnected
Engine struggles to start
Malfunction of the Purge Control Solenoid Valve
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