Knock control

There are two kinds of knock control.

1. Long term adjustments that go into correction factors. ECU applies these to ignition timing across the board to all cylinders based on knock sensor activity that indicates likely long term knock (such as octane).
2. Short term adjustments to timing that the ECU applies on a per cylinder basis. The ECU applies these individually to each cylinder as necessary based on knock sensor activity that indicates an unexpected knock event (such as detonation and/or pre-ignition).