Ignition Control Module: Description and Operation

IGNITION COILS AND IGNITION CONTROL MODULE (ICM)

Ignition Coils And Ignition Control Module (ICM):

Three dual tower ignition coils are mounted to the Ignition Control Module (ICM), and are serviced individually. The ICM performs the following functions:
^ The ICM receives and processes the signals from the 7X CKP sensor.
^ The ICM determines the correct coil triggering sequence. This coil sequencing occurs at start-up, and is remembered by the IC module. After the engine is running, the module will continue to trigger the coils in the correct sequence.
^ The ICM determines the correct direction of the crankshaft rotation, and cuts spark and fuel delivery to prevent backfiring if this condition occurs.
^ The ICM produces and sends low resolution engine speed signals to the PCM.