Ignition System Operation Description

This ignition system does not use a conventional distributor and coil. It uses a crankshaft position sensor input to the Engine Control Module (ECM).

The ECM then determines Electronic Spark Timing (EST) and triggers the electronic ignition system ignition coil. These systems use the EST signal from the ECM to control the EST. The ECM uses the following information:

• Engine load (manifold pressure or vacuum).
• Atmospheric (barometric) pressure.
• Engine temperature.
• Intake air temperature.
• Crankshaft position.
• Engine speed (RPM).