C 2500 Truck 2WD V8-5.7L VIN R (1997)
Ignition Coil: Description and Operation
Ignition Coil Driver Module
The Ignition Coil Driver Module (3, 4 - ICM Bolt) is mounted on a bracket (5, 6, 1-Bracket Attachment Rivet) next to the coil. The VCM signals the
ICD to turn ON primary current to the ignition coil (2) by pulling the IC line high (4 volts). The ICD turns the primary current ON and OFF by applying
and removing the ground to the primary winding at the appropriate time. This module is of minimum function. The module does not contain backup
calibrations that allows the engine to continue to run if the IC signal is lost.
