9000 Aero L4-2290cc 2.3L DOHC Turbo EFI HO (1997)
Ignition Discharge Module: Description and Operation
Ignition
The ignition discharge module is mounted on the camshaft cover over the spark plugs. There are 4 ignition coils in the ignition discharge module, the
secondary windings of which are connected directly to the spark plugs.
The ignition discharge module is supplied with power (B+) from the main relay and connected to ground at grounding point G7P.
When the main relay operates, power (B+) is supplied to the ignition discharge module which converts 12 V to 400 V d.c. and charges a capacitor with
it. This voltage (400 V) is connected to one pole of the primary windings of the 4 ignition coils.
Four trigger leads are connected to the ignition discharge module from Trionic ECM pin 9 (cyl. 1), pin 10 (cyl. 2), pin 11 (cyl. 3) and pin 12 (cyl. 4).
When the engine control module grounds pin 9, the other pole of the primary winding of the ignition coil for cylinder 1 will be grounded (via the B+
input of the ignition discharge module) and the 400 V transformed to a maximum of 40,000 V. Ignition for cylinders 2, 3 and 4 takes place in the same
way.
If there is an open circuit in the power supply or a ground connection to the ignition discharge module, the engine will not start.
