Ignition Control Module: Description and Operation
Component Overview:
The Ignition Timing Control System operates by the Mulit-Point Fuel Injection (MPI) controller controlling the ignition timing through the 2 power transistors. The MPI controller uses all of the engine condition and vehicle operating condition sensors (during normal driving conditions) to compute the correct spark advance or retard. The MPI controller uses the power transistors to control the ignition spark.
The power transistors function to control the ignition timing by interrupting the ignition coils primary current ground causing secondary circuit discharge. The power transistors are solid state components.