Chrysler laser 1990 Technical Information Manual page 166

Battery
To air flow sensor,
crank angle sensor,
idle speed control
Power Supply Control
When the ignition switch on signal is input, the
engine control unit energizes the control relay coil L3
to turn on the S2 switch, thus supplying power to the
injectors, air flow sensor, idle speed control servo,
Fuel Pump Control
When cranking the'engine (ignition switch at the ST
position), the engine control unit energizes the L
coil to turn on the S switch, thus activating the fuel
While operating the engine (ignition switch at the IG
position), the crank angle sensor signal is input to
the engine control unit, which energizes the L,
FUEL SYSTEM - Power Supply Control
Relay control
The engine control unit controls the power suv ' tc
the sensors, engine control unit and actuate,
the control relay.
Ignition switch
Control relay
Fuel pump
control
etc.
Approximately seven seconds after input of the
ignition switch off signal, the unit turns off the S
switch.
control relay coil to keep the SI switch on, thus
continuing to activate the fuel pump.
When the crank angle sensor signal fails to be input
for 0.6 second or longer due to engine stalling,
the engine control unit immediately turns thz. 5
switch off to stop the fuel pump as a safet)
precaution.
Engine
control
unit
Ignition
switch signal