9000 L4-2290cc 2.3L DOHC Turbo EFI (1992)
Ignition Control Module: Description and Operation
Ignition Discharge Module
Ignition timing
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 battery positive voltage (B+) from the main relay and connected to ground at grounding point G7.
When the main relay operates, battery positive voltage (B+) is supplied to the ignition discharge module which convents 12 V to 400 V d.c. and stores
it in the capacitor. The 400 V current is connected to one of the poles of the 4 ignition coils' primary windings.
Connected to the ignition discharge module are 4 trigger leads from DI/APC control module pins 38 (cyl. 1), 19 (cyl. 2), 37 (cyl. 3) and 18 (cyl. 4).
When the control module grounds pin 38, the other pole of the primary winding of the ignition coil for cylinder 1 is connected to ground (via the
ignition discharge module's battery positive (B+) input) and 400 V is stepped up to a maximum of 40 000 V in the ignition coil for cylinder 1. 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.
Ignition control
