Ignition Control Module: Description and Operation

IGNITION COIL & POWER TRANSISTOR (BUILT INTO DISTRIBUTOR)
The ignition coil is built into distributor. The ignition signal from the ECM is sent to the power transistor. The power transistor switches on and off the ignition coil primary circuit. As the primary circuit is turned on and off, the proper high voltage is induced in the coil secondary circuit.
The distributor is not repairable and must be replaced as an assembly except distributor cap and rotor head.