Description And Operation: 2.0L
DESCRIPTION
The knock sensor is made of piezoelectric material. Depending on the vibration frequency of the cylinder walls caused by ignition, the sensor generates voltage proportional to it. The Powertrain Control Module (PCM) detects the voltage value generated by the sensor its rate of change, and as a function of the latter, it can understand whether there is knocking in the cylinder. To reduce the "pinging" caused by knocking, the PCM starts reducing the ignition advance in order to limit the maximum pressure that can be reached in the combustion chamber (the higher the pressure, the greater the risk of knocking). The engine is equipped with two knock sensor located on the crankcase (intake side) near the intake manifold.
OPERATION
The knock sensor:
- detects a knock in one of the cylinders on the corresponding bank
- sends an input signal to the PCM
In response, the PCM retards ignition timing for all cylinders by a scheduled amount.