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ENGINE MANAGEMENT MODULE (EMM)
EXTERNAL SENSORS
Crankshaft Position Sensor
Ribs spaced on the flywheel mark crankshaft posi-
tion. As the ribs p ass th e magnetic field of the
CPS, an AC volt age signal is gene rated. The
EMM uses this sig nal to identify crankshaft posi-
tion and speed, generate a tachometer signal, and
control fuel and ignition timing.
If the sensor is damaged or the signa l is intermit-
tent:
• Below 2000 RPM: 5 occurrences
• Above 2000 RPM: 1 occurrences
the EMM:
Approximate air gap between CPS and flywheel
encoder ribs is 0.073 (1.85 mm).
Use the Evinrude Diagnostics sof tware Monitor
screen to check CPS operation. Th e sof tware
should show an RPM reading while the outboard
is cranking. If the CPS o r its circuit fails, no RPM
reading will appear and the outboard cannot run.
Knock Sensor
Knock sensors (one per cylinder head) detect the
presence of knock (pre-ignition or detonation) dur-
ing the combustion cycle.
When knock is dete cted, the EMM tempo rarily
increases fuel flow and retards ignition timing for
the affected cylinder.
If knock continues, the EMM:
If the sensor circuit is OPEN, the EMM:
Neutral/Shift Interrupt Switch
A swit ch mounted on the po werhead signa ls t he
EMM when the sh ift linkage is moved from FOR-
WARD or REVERSE into NEUTRAL.
A cam on the powerhe ad shift arm closes the
switch in NEUTRAL , comp leting a g round circuit
to the EMM. This signal is used to control:
• Neutral RPM limit
• Shift Interrupt function.
The shift interrupt function shuts off fuel and spark
to three cylinders for approximately one second to
reduce drivetra in lo ads a nd ease shif ting, th en
immediately restores normal eng ine op eration.
The switch mu st be released to its open position
before the shift interrupt function can be activated
again. This circuit does no t fun ction a bove 250 0
RPM.
If t he switch is stuck in th e close d position, t he
EMM:
Stores service code 16
EMM LED 2: OFF (Cranking)
EMM LED 3: ON (Running)
Activates S.A.F.E.
Stores service code 1-6 (code indicates cyl)
Engine Monitor CHECK ENGINE display: ON
Stores service code 7 (port sensor)
Stores service code 8 (stbd sensor)
EMM LED 3: OFF (Cranking)
EMM LED 3: ON (Running)
Engine Monitor CHECK ENGINE display: ON
1. Switch, neutral/shift interrupt
2. Cam
008366
Stores service code 28
EMM LED 3: ON (Running)
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