Functional Description - Ignition Coils
WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.
There is one ignition coil for each spark plug. Each ignition coil s mounted over the top of the spark plug installed in a cavity of the cylinder head. Each coil consists of the following:
- Coil assembly.
- Primary electrical connector.
- Secondary conductor.
- Spark plug boot.
The ignition coils operate in the following manner:
- The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil.
- The Powertrain Control Module (PCM) provides a ground path for the ignition coils.
- The PCM provides a 5 volt control to each ignition coil.
- The ignition coil contains the IGBT (driver) which turns on (energizes) the ignition coil in the presence of the 5 volt control from the PCM. This controls the primary side of the ignition coil operation.
- When the PCM opens the 5 volt control to the ignition coil driver, the ground path is broken and the energy in the coil primary transfers to the secondary ignition (spark plug).
- The ignition coil is designed with a Soft Shut Down (SSD) feature that protects the coil/system due to controller or signal error. The SSD feature is a spark-free de-energized shut-down of the coil after an unexpected extended dwell time.