Electronic Ignition System

Ignition system circuit consists of a battery, distributor, ignition switch, spark plugs, igniter, and primary and secondary wiring. An Ignition Control (IC) system is used that is monitored and controlled by the ECM. An ignition noise suppressor condenser and noise suppressor filter, are used. Noise suppressor filter provides ignition signal for tachometer (if equipped).

Distributor uses a signal generator (signal rotor and pick-up coil/Camshaft Position (CMP) sensor) and rotor to produce reference signals for the ECM. All spark timing changes within distributor are performed electronically by ECM.

Ignition coil power is provided through 20-amp IG fuse located in fuse/relay block, below left side of instrument panel. Fuse receives power when ignition is turned on.

Ground circuit for ignition coil is regulated by the ECM through igniter. On vehicles with standard emission system, igniter is located inside ECM. On upgraded emission system, igniter is located under ignition coil and mounted on right side of firewall in engine compartment. As rotating signal rotor passes pole piece of pick-up coil/CMP sensor, a reference signal is sent to ECM. ECM uses this signal to determine when to signal igniter to open ground circuit for primary ignition.

When igniter opens ground circuit for primary ignition, magnetic field around ignition coil windings collapses, producing an induced high voltage surge used to operate the spark plugs. Igniter sends a signal back to ECM to confirm primary ignition circuit operation was completed.