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Knock control

Knock control


If knocking occurs in any of the cylinders, the knock sensor sends a signal to the control module. The control module notes the cylinder in which knocking occurs and retards the ignition in that cylinder by 3°.

If the knocking stops as a result of retarding the ignition, the timing will be restored in steps of 0.5° to what it was before.

On the other hand, if knocking persists in the same cylinder despite its ignition point being retarded by 3°, the control module will retard it additionally in steps of 3° up to a maximum of 13° BTDC.

At full engine load the ignition point in all cylinders is retarded by 6° to prevent knocking. When the engine load is reduced, the ignition is restored to normal in steps of 0.5°.

Should a break in continuity occur in the knock sensor of the sensor circuit, the ignition will be retarded by 13ø in all cylinders (at engine speeds >2000 rpm) at the same time as the CHECK ENGINE lamp (MIL) lights up.