OBD I - Electronic Ignition System (EI High Data Rate)

DESCRIPTION AND OPERATION
The Electronic Ignition (EI) system consists of the following components:

Crankshaft Position (CKP) sensor:

1. Crankshaft Position (CKP) sensor.

Ignition Control Module (ICM):

2. Ignition Control Module (ICM).

Ignition coil:

3. Ignition coil.
4. The spark angle portion of Powertrain Control Module (PCM).
5. Related wiring.

The EI (High Data Rate) Ignition System operates by sending crankshaft position information from the 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 that is sent 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 Ignition Diagnostic Monitor (IDM) signal to the PCM which is used to indicate a failure mode and also provide a tach output signal.