Ignition Control Module: Description and Operation

Typical Ignition Module Assembly:

The C3I ignition module monitors the camshaft sensor and the crankshaft sensor signals. This information is transmitted to the ECM so that the correct spark and ignition timing can be maintained during all driving conditions. During cranking, it monitors the cam signal or "Sync Pulse" to begin the ignition firing sequence. Below 400 rpm, the module controls spark advance by triggering each of the three coil packs at a pre-determined interval based on engine speed only. Above 400 rpm, the ECM controls the spark timing (EST) and compensates for all driving conditions. The C3I module must receive a cam signal then a crank signal in than order to enable the engine to start. The C3I module is not repairable. When a module is replaced, the coils must be transferred to the new module.