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.
If the knock sensor signal is outside the acceptable parameters, P1550 is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
Circuit continuity check, pulse test
Poor connection
Open or short in control circuit
Knock sensor
Enable Conditions
-
Threshold Value
IC circuit internal fault
Diagnostic Time
Continuous
MIL ON Condition
DTC only
Specification
Capacitance (pF)
950 ~ 1350
Resistance (O)
4.87