Ignition Control Module: Description and Operation

PURPOSE
The power transistor controls ignition current by interrupting the ignition coil primary ground causing secondary circuit discharge.

Power Transistor Location:

LOCATION
The power transistor located On the front of the cylinder head, near the ignition coils.

OPERATION
The ECU controls ignition timing through the power transistor. The power transistor is a type of switch that allows a very low voltage (from the ECU) to control a larger amount of voltage (negative side of coil). During engine cranking, the ignition timing is fixed at 5°BTDC