2. Ignition principle

Ignition consists in igniting the compressed air-fuel mixture in the engine's combustion chamber at the desired moment to initiate combustion in the cylinder.

To ignite, at least part of the air-fuel mixture must undergo a temperature rise that raises it above its auto-ignition temperature. The energy required for this temperature rise is provided by a spark. The spark is created by a potential difference between two electrodes on the spark plug. To create this spark, the spark plug is supplied with high voltage by an ignition coil. The ignition coil is powered and controlled by the engine control unit (ECU). The coil's electrical connection to the spark plug is ensured by a spring located in the coil's high-voltage nose. On remote ignition systems, the connection to the spark plug requires the installation of special cables, known as high-voltage harnesses....