Bonneville V6-231 3.8L VIN 3 SFI (1988)
Knock Sensor: Description and Operation
To control spark knock an electronic spark control (ESC) system is used. This system is designed to retard timing up to 10~ to reduce spark knock in the
engine. This allows the engine to use maximum spark advance to improve driveability and fuel economy.
A knock sensor is mounted on the engine. When a knock occurs, the knock sensor genereates an AC voltage signal that the ECM detects. The ECM
responds by retarding the ignition timing a maximum of 10°, or until the knock ceases. When the knocking stops, ingition timing is advanced back to its
pre-programmed point for the engine operating conditions.
