Ignition Control Module: Description and Operation

PURPOSE
The distributor reference signal provides the ECM with both engine RPM and crankshaft position information. This enables the ECM to operate the fuel pump relay and energize the fuel injector.

OPERATION
When the engine is cranking or running the ECM receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire becomes open or grounded the engine will not run, as the ECM will not operate the injector.