Ignition System: Description and Operation

The 20 valve turbo engine has direct high tension ignition that does not use an ignition distributor.

Ignition Coils 20V:

Each cylinder has its own ignition coil. The ignition coils are located directly above each spark plug. This type of ignition system ensures good spark, even during high engine loads during maximum boost.

Each coil is secured to a cover plate on top of the valve cover with four screws which also supplies the ground for each coil. Each coil can be replaced as a separate unit. A ground wire from the cover plate to the cylinder head helps ensure a good ground connection for the secondary windings.

Power Stages 20V:

The ignition system uses power output stages to control the output of the coils. Two power output stages are used, one controls the ignition coils for cylinders 1,2 and 3 and the other controls the coils for cylinders 4 and 5.

Each power output stage has three switching units. The Motronic ECM, based on inputs from the Camshaft Position Sensor and the crankshaft position sensor will then supply a ground for the primary side of the ignition coil.