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Ignition advance is controlled by the ECU. Inputs from fuel injection ECU (barometric), Hall sensor (ignition pulses), and coil (RPM) are used by ECU to determine correct advance. ECU then resets ignition timing by transmitting signals to ignition system which opens primary circuit and triggers spark.

A detonation sensor detects any knocking in the engine and applies a signal to the ECU which then automatically retards ignition timing in accordance with programmed parameters and engine load and speed input signals received.

The knocking related ignition timing is controlled on individual cylinders. The ignition timing may vary from one cylinder to the next. However, load related timing is controlled for all cylinders together.