G 20 Van V6-262 4.3L VIN Z (1993)
Knock Sensor: Description and Operation
With 4L80E Automatic Transmission
Electronic Spark Control Circuit
Purpose:
The Knock Sensor (KS) sends a signal to the powertrain control module (PCM) to retard ignition timing during spark knock conditions.
Operation:
The knock sensor is a piezoelectric device. A ceramic crystal vibrates with engine knock. The vibration of the crystal produces a voltage signal
which is relayed to the control module where the signal is interpreted by the control module and used to calculate necessary ignition timing
adjustments.
When the knock sensor senses no more knocking the PCM advances timing in small increments. This allows the control module to maintain
maximum timing advance under various conditions.
Location:
The knock sensor is located in the engine block.
