Knocking is a phenomenon characterized by undesirable vibration and noise that can cause engine damage. A knock sensor (KS) is mounted on the cylinder block and senses engine knocking. A knocking vibration from the cylinder block is applied as pressure to the piezoelectric element. A knock sensor (KS) detects vibration when RPM rises or drops and generates voltages based on this vibration. The ECM controls the ignition timing based on the amplitude and frequency of the knock sensor signal. For example, if engine knocking occurs, the ignition timing is retarded to prevent it.
The ECM monitors the range of the analog input signal from knock sensor to check sensor failure that is short circuit or open circuit. If the difference between knock signal and noise level is smaller than the threshold during defined time period, the DTC P0326 is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check
Poor connection
Open or short to ground in signal circuit
Knock sensor
Enable Conditions
IG ON
Battery voltage 10~16V
Engine Coolant Temperature ?40?
Engine speed ?3200rpm
Engine Load?0.5 ~ 0.7
Threshold Value
Normalized reference level < lower limit, f(rpm)
Diagnostic Time
5sec
MIL ON Condition
NO MIL