Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the logical successor to CHARM, I recommend you try it!

Link: lemon-manuals.la

Knock Sensor: Testing and Inspection

Knock Sensor Cutaway:




The scan tool has several parameters for diagnosing the KS circuit.
^ Knock retard indicates the amount of spark the PCM is removing from the IC spark advance in response to the signal from the knock sensors.
^ Spark Indicates the amount of spark advance being commanded by the PCM on the IC circuit.

DTC P0325 indicates that the KS system is malfunctioning. DTCs P0327 and P0332 indicates that a Knock sensor or Knock sensor circuit is malfunctioning. If these DTCs are set, Refer to applicable DTC table.