Ignition System Components

Component Locations:

The Electronic Ignition (EI) system consists of the following components:
^ Camshaft Position (CMP) sensor
^ ignition coil
^ the spark angle portion of Powertrain Control Module (PCM)
^ related wiring

Camshaft Position (CMP) Sensor
The camshaft position sensor:
^ is a variable reluctance sensor.
^ is triggered by the high point mark on the LH exhaust camshaft.
^ provides camshaft rotational location information to powertrain control module.

The powertrain control module uses the camshaft position (CMP) signal for ignition coil fire sequencing. The powertrain control module also uses the CMP signal for fuel injector synchronization.

Ignition Coil
The engine uses eight separate ignition coils. Each ignition coil is controlled by the powertrain control module.

Each ignition coil is mounted directly above each spark plug and activates its own spark plug in the correct sequence as controlled by the powertrain control module.

Failure Mode Effects Management
During some electronic ignition system concerns, the failure mode effects management portion of the powertrain control module will maintain vehicle operation if the spark output signal is interrupted. The powertrain control module will automatically turn the ignition coils ON and OFF using the CKP signal input. This will result in fixed-spark timing (10 degrees BTDC) and fixed dwell time (no CCD).
^ If the powertrain control module loses CMP input while the engine is running, the powertrain control module will retain the correct firing sequence and it will continue to fire the ignition coil to maintain engine operation.

Ignition Diagnostic Monitor
The ignition diagnostic monitor is a function of the powertrain control module. The powertrain control module stores the information for use during diagnostic test mode.