Knock Sensor: Description and Operation

Knock Sensors G61 & G66:

Electrical Circuit - Knock Sensors G61 & G66:

Knock Sensors G61 and G66:
The electronic ignition-timing control perates in combination with selective preignition control for the individual cylinders. The ability to detect knock at the respective cylinders is enhanced through installation of two knock sensors. The process used to identify the affected cylinder(s) is assisted by signals from the camshaft Position sensor.
The system responds to recognized preignition at a given cylinder by initiating gradual reductions in the timing advance angle. The system continues to move back the timing until the knock disappears.
The system responds to malfunctions at G61 and/or G66 by retarding the ignition angle for all cylinders and enriching the mixture.