Federal Emissions
Typical Ignition Module Assembly:
Ignition System Circuit Diagram:
PURPOSE
The Electronic Ignition (EI) module monitors the crank sensor signals and based on these signals sends a reference signal to the ECM so that correct spark and fuel injector control can be maintained during all driving conditions.
OPERATION
During cranking, the EI module monitors the "sync pulse" to begin the ignition firing sequence, and below 400 rpm the module controls spark advance by triggering each of the three coils at a pre-determined interval based on engine speed only. Above 400 rpm, the ECM controls the spark timing through the module, and compensates for all driving conditions. The EI module must receive a "sync pulse" and then a crank signal in that order to enable the engine to start.
DIAGNOSTIC NOTES:
The EI module is not repairable. When a module is replaced, the remaining EI module components must be transferred to the new module.