Ignition Management

The firing cylinder has the proper air/fuel ratio, now ignition must be optimized for performance and emissions.

Fig 1: Engine Management System GN T ON Management

Courtesy of BMW OF NORTH AMERICA, INC.

The EMS2000 again relying on previously analyzed sensor inputs, decides upon the correct time for ignition coil firing. As the engine approaches TDC, the EMS2000 grounds the appropriate output stage and fires the ignition coil, then listens through the knock sensor for variations in engine sound.

The spark plugs introduce the ignition energy into the combustion chamber. The high voltage "arcs" across the air gap in the spark plug. This creates a spark which ignites the air/fuel mixture.

Failure of the camshaft sensor has no effect on the ignition system as the coils are fired every revolution as a function of the waste spark system.

Failure of the crankshaft sensor causes immediate cut off of ignition.

Fig 2: Engine Management System EM SS ON Management

Courtesy of BMW OF NORTH AMERICA, INC.