Electronic Ignition: Notes

2004 Oldsmobile Bravada AWDSECTION Notes
WARNING: This page is about a different car, the 2003 Pontiac Grand Prix, 2003 Chevrolet Malibu, and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

The Electronic Ignition (EI) 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 uses an individual coil for each cylinder. The ignition coils and Ignition Control Module (ICM) are contained within two assemblies, one for each cylinder bank. The assemblies are mounted in the center of each camshaft cover, with short boots connecting the coils to the spark plugs. The driver modules within each ICM are commanded ON/OFF by the Powertrain Control Module (PCM). The PCM primarily uses engine speed and position information from the Crankshaft Position (CKP) and Camshaft Position (CMP) sensors to control the sequence, dwell, and timing of the spark. The EI system consists of the following components:

  • CMP sensor.
  • Camshaft reluctor wheel.
  • CKP sensor.
  • Crankshaft reluctor wheel.
  • Ignition Coil/ICM assembly.
  • PCM.

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