Secondary Ignition Monitor

The MS41.1 system uses a shunt resistor to additionally monitor the secondary ignition for misfire. The resistor layout is similar to the Bosch Systems.

The resistor is located in the wiring tray below the ignition coils. It is connected in parallel to the ground lead (KL 4a) for the coils. As the secondary magnetic field collapses, a voltage spike is induced in the windings. The control module monitors the voltage drop across the resistor as an indication of coil firing. If a signal is missing, the control module detects the affected cylinder from the camshaft position sensor input.