Ignition Control Module: Description and Operation

The Igniter, located near the coil on the left side of the engine compartment, is a switching device that activates the primary ignition coil circuit. The ECU determines optimum ignition timing from various inputs and transmits a primary current "OFF" signal to the igniter to control ignition timing.

The ECU calculates input from these devices to control ignition timing:

Distributor Ne signal
Distributor G signal
Water thermosensor
Airflow meter
Atmospheric pressure sensor
EC-AT control unit
Knock control unit
Throttle sensor/idle switch
Ignition switch ("START" position)
A/C switch
EGR position sensor
Test connector (for base timing adjustment)