Distributor Ignition System
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The Distributor Ignition (DI) system is responsible for producing and controlling a high energy secondary spark. This spark is used to ignite the compressed air/fuel mixture at precisely the correct time. This provides optimal performance, fuel economy and control of exhaust emissions. This ignition system consists of a single ignition coil and Ignition Control Module (ICM). Spark energy is delivered via a distributor cap, rotor, and secondary spark plug wires. The driver module within the ICM is commanded to operate the coil by the PCM, that has complete control over spark timing. The DI system consists of the CKP, CMP, ignition coil and ICM, secondary ignition and PCM.