Ignition Timing Control System

Ignition Timing Advance Control -- Ignition timing is totally computer controlled by the ignition ECU. Ignition timing is based on preprogrammed information and modified by inputs from the engine sensors.

Detonation (Knock) Retard Operation -- Knock sensors are fitted to the cylinder blocks to sense detonation inside the cylinders. When detonation is detected, the ignition ECU retards ignition timing. On 4-cylinder engines, ignition timing is retarded only in the cylinder(s) where detonation has been detected. On 6-cylinder engines, ignition timing is retarded in cylinder pairs. On either style engine, timing will be retarded gradually until detonation ceases.