Ignition Timing Control System

Ignition Timing Control System provides detonation control, cold timing control and high altitude timing control. When detonation occurs, ignitor retards ignition timing (maximum 12 degrees crankshaft angle) until detonation is eliminated. If detonation sensor has an open or short circuit, ignitor retards ignition timing by a fixed angle (8 degrees crankshaft angle) to prevent detonation. This is a fail-safe feature.

When engine coolant temperature is low or vehicle is at an altitude of 3937 ft. (1200 m) or higher, ignition timing is advanced a fixed angle (5 degrees crankshaft angle) to improve mileage and driveability.