General System Description

DESCRIPTION
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. The Electronic ignition system 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.

The electronic ignition system does not use the conventional distributor and coil. The ignition system consists of the following components/circuits:
^ Eight ignition coils/modules.
^ Eight Ignition Control (IC) circuits.
^ Camshaft Position (CMP) sensor.
^ 1X Camshaft reluctor wheel.
^ Crankshaft Position (CKP) sensor.
^ 24X Crankshaft reluctor wheel.
^ Related connecting wires.
^ Powertrain Control Module (PCM).

POWERTRAIN CONTROL MODULE (PCM)
The PCM is responsible for maintaining proper spark and fuel injection timing for all driving conditions. To provide optimum driveability and emissions, the PCM monitors input signals from the following components in calculating Ignition Control (IC) spark timing:
^ Engine Coolant Temperature (ECT) sensor.
^ Intake Air Temperature (IAT) sensor.
^ Mass Air Flow (MAF) sensor.
^ Trans Range inputs from Transaxle Range switch.
^ Throttle Position (TP) sensor.
^ Vehicle Speed Sensor (VSS).