Evinrude E-tec 75 HP, Service Manual

Page: 114 / 344

114
SYSTEM ANALYSIS
IGNITION AND ELECTRICAL CIRCUITS
IGNITION AND
ELECTRICAL CIRCUITS
Following is a complete list of circuits required for
ignition output:
Stop Circuit
•
Outboard running: black/yellow wire NOT
grounded (emergency stop switch lanyard in
place).
Neutral Switch
•
Powerhead mounted neutral switch provides a
switched ground circuit to
EMM
. The circuit
enables specialized control functions such as
neutral start protection and RPM limiting in
NEUTRAL.
Stator Output Voltage
•
Provides
EMM
with A/C voltage.
•
Outboard cranking: 30 V to
EMM
J2 connector.
•
Outboard running: 55 V to
EMM
J2 connector
EMM
•
Stator output to
EMM
provides voltage to
EMM
’s internal power supply.
EMM
digital
ground, ignition grounds, and injector grounds
must be functional.
Crankshaft Position Sensor
•
Provides
EMM
with input.
•
Outboard cranking speed exceeds 300 RPM
and a steady CPS signal is generated.
Alternator Output Voltage
•
Alternator output from
EMM
(white/red) pro-
vides 55 V to the high pressure fuel pump, the
oil injector pump, the fuel injectors, and the igni-
tion module of
EMM
.
Capacitor
•
Connected to 55 V circuit (white/red) to stabilize
current on 55 V circuit.
•
Negative terminal of capacitor must be
grounded.
Ignition Power Supply to
EMM
•
55 V to pins 3 and 4 of
EMM
J1-B connector.
Ignition Primary Voltage
•
Output from
EMM.
•
EMM
provides 200 V output to orange ignition
primary wires. Minimum required voltage is
130 V.
Ignition Coil
•
EMM
provides input to primary winding of coil.
•
Output from ignition coil secondary winding and
high tension spark plug wire.