Ignition coils, function - GF15.10-P-3102-02AM
Engine 113 has two spark plugs per cylinder.
Each spark plug is actuated separately via its own ignition coil by the ME control unit. Both ignition coils of a cylinder are combined to form a dual ignition coil.
The ME-SFI [ME] control unit actuates the primary wirings of the double ignition coil simultaneously at terminals 1a and 1b with ground. The primary current flows are interrupted at the moment in time of ignition timing. Sudden collapse of the magnetic fields causes the ignition voltages to be induced in the secondary windings. The ignition voltages pass to the respective spark plugs via the high-voltage terminals, the ignition cable and the spark plug connector.
The voltage supply for the double ignition coils is provided via "circuit 15 fused".
Diodes are built-in to suppress additional ignition sparks when the primary current is switched on.
Because of these diodes, it is not possible to measure the resistances of the secondary windings.