Ignition Control Module: Description and Operation

Ignition Coil And Power Transistor Circuit:

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

LOCATION
The power transistor is located on the left inner fender with the coil.

OPERATION
The ECM controls ignition timing through the power transistor. The power transistor is a type of switch that allows a very low voltage (from the ECM) to control a larger amount of voltage (negative side of coil).