Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the logical successor to CHARM, I recommend you try it!

Link: lemon-manuals.la

Ignition Timing: Adjustments

CIRCUIT DESCRIPTION
The enhanced ignition system uses the Crankshaft Position (CKP) sensor in order to provide a timing input to the control module. Ignition Control (IC) spark timing for each cylinder based on this input. The control module provides the ignition timing signal to the Ignition Control Module (ICM) to control the ignition coil. Each timing pulse detected by the ICM allows it to energize the ignition coil. A large secondary ignition voltage is induced in the secondary coil by the primary coil. This high voltage is switched to the correct spark plug by the distributor.