Ignition Timing Adjustment

If knock continues to occur, ignition timing is adjusted in retard direction until it reaches the maximum adjustment value. When knock stops occurring, the retard adjustment is returned in stages until normal characteristics map value is satisfied.

ECM adjusts ignition timing by cylinder according to input signals. When the knock sensor detects knock in the cylinders, the ignition timing of the applicable cylinder is adjusted in retard direction (according to engine speed), starting from consequent ignition.

If knock continues to occur relatively long, ECM decreases engine output to protect the engine.