When the ignition switch is turned to the ON position, battery voltage is applied to the ignition coil primary winding. As the engine is being cranked and the distributor shaft rotates (1.8L engine), ignition signals are transmitted from the Multi-Point Injection (MPI) control unit to the power transistor. The power transistor now begins controlling the coil primary circuit by repeatedly grounding. As a result, a high voltage is induced in the secondary winding of the ignition coil. From the ignition coil, the secondary winding current flows through the distributor and spark plug to ground, thus causing ignition in each cylinder.
The operation of the ignition system for the 1.6L and 2.0L DOHC engines is the same as the conventional pointless distributor engines, with the exception of the signal being transmitted to the MPI control unit. These signals are transmitted as the crank angle sensor shaft rotates. Because these engines are not equipped with a distributor, the high voltage flows directly from the ignition coil secondary winding through the spark plug, thus causing ignition in each cylinder.