System Description

PURPOSE
In the Electronic Ignition System (EI), all engine timing and spark distribution is electronic, with no moving parts. During basic operation, the Powertrain Control Module (PCM) determines the ignition timing. The Ignition Control Module (ICM) determines which ignition coil to use.

OPERATION
This System operates by sending crankshaft position information from the Crankshaft Position (CKP) sensor to the ICM. The module generates a Profile Ignition Pickup (PIP) signal and sends it to the PCM.
The PCM responds with a Spark Output (SPOUT) signal containing advance or retard timing information back to the ICM. The module processes the CKP and SPOUT signals and decides which coils to fire. In addition, the module generates an Ignition Diagnostic Monitor (IDM) signal to the PCM which is used to indicate a failure mode and also provide a tach output signal.

FEATURES
Repetitive Spark is used to improve idle stability. It is enabled by the PCM program below 1000 rpm.In the repetitive spark mode, after the first spark is sent to a pair of spark plugs, the plugs will be re-struck up to three more times very quickly. The repetitive spark primary waveform can be seen using an engine analyzer with El capability.



COMPONENTS
The electronic ignition system consists of the following:
^ Crankshaft Position Sensor (CKP) sensor
^ Ignition Control Module (ICM)
^ 4-Tower Coil Pack
^ The desired spark angle signal from the Powertrain Control Module (PCM)
^ Related wiring