Function of the ignition module - GF15.15-P-3101-03M
An L/C/R coil/condenser/resistance) - oscillating circuit with control and regulating circuit generates a 180 volt AC voltage (primary voltage) for every spark plug. This is then stepped up in the ignition coils above in the spark plug sockets to create the ignition voltage (secondary voltage).
Once ignition has taken place there is then a switch-over to the auxiliary voltage of about 23 volts. This is used to measure the ion currents at the spark plugs.
The ion current signal is decoupled in the ignition module, filtered and then transferred over a screened cable to the ME control unit.