Hyundai Sonata: Knock Sensor (KS). Description and Operation
Description
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.

Camshaft Position Sensor (CMPS). Repair procedures
Inspection
1.
Check the signal waveform of the CMPS and CKPS using the GDS.
Specification:
Refer to “Wave Form”
...
Knock Sensor (KS). Specifications
Specification
Item
Specification
Capacitance (pF)
850 ~ 1,150
...
See also:
Gasoline containing alcohol and methanol
Gasohol, a mixture of gasoline and ethanol (also known as grain alcohol), and
gasoline or gasohol containing methanol (also known as wood alcohol) are being marketed
along with or instead of leade ...
If the engine will not start
If engine doesn't turn over or turns over slowly
1. If your vehicle has an automatic transaxle, be sure the shift lever is in
N (Neutral) or P (Park) and the emergency brake is set.
2. Check t ...
Opening the fuel filler lid
The fuel filler lid must be opened from inside the vehicle by pushing the fuel
filler lid opener button.
✽ NOTICE
If the fuel filler lid will not open because ice has formed around it, ...
