Service Manual 5008736_55 MFE Engine Managment Module [External Sensors]

Monitors the EMM’s 5 V sensor circuit.

If sensor voltage is less than 4.75 volts, the EMM.

Supplies the EMM with barometric pressure reading to compensate for changes in altitude and air density.

If the BP sensor reads less than 13.3 KPa or greater than 119.0 KPa, or the sensor or circuit fails, the EMM:

If the BP sensor reads less than 70 KPa, the EMM:

If the BP sensor reads greater than 105 KPa, the EMM:

Sensor inputs and intern al EMM controllers a re used to control outboard operation. Use Evinrude Diagnostics software to troubleshoot the sensors. Refer to the EMM Service Code Chart at the back o f this manual for a complete list of all engine fault codes.

The EMM provides a 5 V DC signal for sensor circuits. It monitors all sensor volt age inputs and compares them to predetermined accept able ranges. Inputs that fall outside of the acceptable range create service codes.

Air Temperature Sensor

The air temperature sensor monitors the air temperature at the throttle body.

If t he AT sensor voltage is out of the expected range, or the sensor or circuit fails, the EMM:

Monitors cylinder head temperature.

If cylinder head temperature exceeds 194° F (90° C), the EMM:

If cylinder head temperature exceeds 230°F (110°C), the EMM:

If sensor values are below -15 °F ( -26.2°C) or above 332°F (166.5°C), the EMM:

If sensor values are below -4°F (-20°C), the EMM:

If cylinder head does not reach operating temperature (104°F / 40°C below 2300 RPM) in 10 minutes, the EMM:

The low oil switch monitors the oil level in the oil tank.

If the oil level falls below one-quarter capacity, the EMM:

When the oil level falls below o ne-quarter, the EMM begins counting oil pump pulse cycles. When it reaches 4800 pulses, the EMM:

To recover from S.A.F.E. mode:

• Oil level must be above one-quarter
• The warning reset s after three oil pump pulse cycles when the outboard h as been stopped and restarted.

If outboard h as bee n run for more than 3 hours with NO OIL faults (codes 34 & 117), the EMM.

The throttle position sensor receives a voltage signal from the EMM. As the throttle lever is rotated, the EMM receives a return voltage signal through a second wire. This signal increases as the TPS lever is advanced. A third wire provides a ground
circuit back to the EMM.

If TPS voltage is greater than 0.78 volts when the recoil starter is pulled, the EMM:

If the outboard starts, the code is saved.

If code 11 is present as both a Active Fault and a Occurred Fault, refer to Throttle Cable Adjustment on p. 231.

If the TPS or TPS circuit fails (below 0.14 volts or above 4.92 volts), the EMM:

IMPORTANT: When a TPS circuit fault has been detected, the outboard will not accelerate above idle speed. To reset, stop the outboard and correct the fault.

If the TPS circuit reads below 0.2 volts, the EMM:

If the TPS circuit read s above 4.85 volt s, the EMM:

Ribs spaced on the flywheel mark crankshaft position. As the ribs p ass the magnetic field of the CPS, an AC volt age signal is generated. Th e EMM uses this signal to identify crankshaft position and speed, generate a tachometer signal, and control fuel and ignition timing.

If the sensor is damaged or the signal is intermittent (10 occurrences), the EMM:

Approximate air gap between CPS and flywheel encoder ribs is 0.073 (1.85 mm).

Use the Evinrude Diagnostics software Monitor screen to check CPS operation. The software should show an RPM reading while the outboard is cranking. If the CPS or its circuit fails, no RPM reading will appear and the outboard cannot run.

The powerhead mounted neutral switch controls a ground signal from the EMM to indicate shift linkage position. This allows the EMM to control idle speed variations and start in gear protection. Fuel and ignition functions are turned off if the neutral switch is not closed.

If the starter is cranked while t he outboard is in gear, or if the switch fails, the EMM:

The Monitor screen of the diagnostics program displays switch position, NEUTRAL or IN GEAR. Make sure switch is operating properly.