Electronic Ignition System

ELECTRONIC IGNITION
The electronic ignition system controls fuel combustion by providing a spark to ignite the compressed air/fuel mixture at the correct time. To provide optimum engine performance, fuel economy, and control of exhaust emissions, the PCM controls the spark advance of the ignition system. Electronic ignition has the following advantages over a mechanical distributor system:
^ No moving parts.
^ Less maintenance.
^ Remote mounting capability.
^ No mechanical load on the engine.
^ More coil cool down time between firing events.
^ Elimination of mechanical timing adjustments.
^ Increased available ignition coil saturation time.

IGNITION CONTROL
The Ignition Control (IC) spark timing is the PCM's method of controlling the spark advance and the ignition dwell.
The IC spark advance and the ignition dwell are calculated by the PCM using the following inputs:
^ Engine speed.
^ Crankshaft position (58X reference).
^ Camshaft position (CMP) sensor.
^ Engine coolant temperature (ECT) sensor.
^ Throttle position (TP) sensor.
^ Knock signal (knock sensor).
^ Park/Neutral position (PRNDL input).
^ Vehicle speed (vehicle speed sensor).
^ PCM and ignition system supply voltage.