Chrysler laser 1990 Technical Information Manual page 77

IGNITION SYSTEM
Sensors
The ignition system is a two-coil ignition system that
supplies sufficient energy for ignition up to high
speeds. This engine does not have a distributor
since the engine control unit directly activates the
power transistor for ignition timing control.
The functions and controls of the engine control unit
and various sensors that control the ignition timing
are described in the next chapter, IGNITION CON-
TROL SYSTEM.
This ignition system has two power transistors and
two ignition coils. Power transistor "A" controls the
primary current of ignition coil "A" to activate the
ELECTRICAL - Engine Electrical
1 I
Power transfstor
speed detectton
spark plugs of the No.1 and No.4 cylinders.
Similarly, power transistor "B" controls ignition coil
"B" which activates the spark plugs of the No.2 and
cylinders are activated but actual ignition takes place
only in the single cylinder that is on its compression
stroke, because the other is on its exhaust stroke at
that time.
Power transistors "A" and "B" are activated by
signals from the engine control unit, that controls
which cylinder is fired at what time.
8-25
Battery