Buick LeSabre 1986-1999
Buick Park Avenue 1996-1999
Oldsmobile 88 1992-1999
Oldsmobile Delta 88 1986-1988
Oldsmobile LSS 1996-1999
Pontiac Bonneville 1987-1999
The vehicles covered by this manual are equipped with a Computer Controlled Coil (C 3 I) ignition system. On later models, this system may also be called the Electronic Ignition (EI) system. The C 3 I (or EI) system is distributorless, and consists of 3 ignition coils, an Ignition Control Module (ICM), dual crank sensor, camshaft sensor, connecting wires, and the Electronic Spark Timing (EST) portion of the Electronic Control Module (ECM).
The ECM uses the EST circuit to control spark advance and ignition dwell, when the ignition system is operating in the EST mode. There are 2 modes of ignition system operation. These modes are as follows:
- Module mode - the ignition system operates independently of the ECM/PCM, with module mode spark advance always at 10 degrees BTDC. The ECM has no control of the ignition system when in this mode.
- EST mode - the ignition spark timing and ignition dwell time is fully controlled by the ECM. EST spark advance and ignition dwell is calculated by the ECM.
To control spark knock, and to use maximum spark advance to improve driveability and fuel economy, an Electronic Spark Control (ESC) system is used. This system consists of a knock sensor and the ECM. The ECM monitors the ESC signal to determine when engine detonation occurs.