Ignition System: Notes

The electronic ignition system does not use the conventional distributor and coil. The ignition system consists of three ignition coils, an ignition control module, a camshaft position sensor, 2 crankshaft position sensors, an engine crankshaft balancer with interrupter rings attached to the rear, related connecting wires, and the Ignition Control (IC) and fuel metering portion of the PCM.

The EI systems on the 3400 (LA1) engine uses a coil pack with one ignition coil for every two cylinders in the engine. Mounted under the ignition coils on each system is an ignition control module (ICM) that performs ignition coil switching functions and interacts with the powertrain control module (PCM) to optimize ignition system operation. On these engine systems, the spark timing is controlled electronically. The ICM controls the spark timing during engine start-up, and provides a back-up timing system that will allow the engine to run in the event of an open or ground in the ignition control (IC) circuit. Once the engine starts and is running above approximately 400 RPM, the PCM takes over the spark timing and sends signals to the ICM for ignition coil switching.