Operation CHARM: Car repair manuals for everyone.

System Description

BASIC OPERATION STRATEGY
When the ignition power transistor unit is switched on by the signals from the engine control module, the primary current of the ignition coil will flow. When the ignition power transistor unit is switched off, the primary current flow is interrupted, and high voltage is produced at the secondary coil.

When the engine control module switches off the transistor within the unit, the battery positive voltage within the unit is applied to the ignition power transistor unit, and the ignition power transistor unit is switched on. In addition, the ignition power transistor unit is switched off when the engine control module switches on the transistor within the unit.