SAAB WIS ONLINE

Ignition coil unit (552), Simtec

Ignition coil unit (552), Simtec

Location

Ignition coil unit (552)

Principal use

The ignition coil has the following task:


- Generate the high-voltage spark that starts the combustion.


These signals are used for knock control, synchronisation of ignition timing/fuel injection and for misfire detection.

Type

Assembly with 4 inductive ignition coils.


Connection

Pin No. Signal type Description
2 B-, in +15 power supply from fuse 4 (342)
3 Ignition trigger, in Ignition trigger, cyl 4 from ECM.
4 Ignition trigger, in Ignition trigger, cyl 3 from ECM.
5 Ignition trigger, in Ignition trigger, cyl 2 from ECM.
6 Ignition trigger, in Ignition trigger, cyl 1 from ECM.


The unit contains four individual ignition coils. The ignition coil is a transformer whose primary winding is supplied +15 (pin 2 on the ignition coil unit). The current through the primary winding is regulated by ECM. When ECM grounds one side of the primary winding, a current flows through the same. The time during which this current flows is called cam angle or charging time. When current ceases, the spark is fired. This time point is the same as the actual ignition angle. ECM determines both the ignition coil charge time (cam angle) and the ignition angle.

Wiring diagram