Service Manual 250-300 HP 3.4 L E-TEC Engine Managment Module [External Sensors]

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

If the BP sensor reads less than 13 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:

The exhaust pressure sensor monitors exhaust pressure during all running conditions to compensate for engine loads.

If the sensor reads less than -85 in. water, or greater than 85 in water, or the sensor or circuit fails, the EMM:

If exhaust pressure is less than 40 in. water, the EMM:

If exhaust pressure is greater than 80 in. water, the EMM:

Sensor inputs and internal EMM controllers are used to control outboard operation. Use Evinrude Diagnostics software to troubleshoot the sensors. Refer to the EMM Service Code Chart at the back of 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 voltage inputs and compares them to predetermined acceptable ranges. Inputs that fall outside of the acceptable range create service codes.

Air Temperature Sensor

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

If the AT sensor voltage is out of the expected range, or the sensor or circuit fails, the EMM: Stores service code 47

Engine Temperature Sensor

Monitors cylinder head temperature.

If PORT cylinder head temperature is greater than 212°F (100°C) below 2000 RPM, or greater than 194°F (90°C) above 2000 RPM, the EMM:

If STBD cylinder head temperature is greater than 212°F (100°C) below 2000 RPM, or greater than 194°F (90°C) above 2000 RPM, the EMM:

If cylinder head temperature is greater than 248°F (120°C), the EMM:

The outboard will not restart until the engine temperature returns to normal. Refer to SHUTDOWN MODE on p. 100.

If sensor values are less than -13°F (-25°C), or greater than 329°F (165°C), the EMM:

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

If PORT cylinder head temperature is greater than212°F (100°C) below 2000 RPM, or greater than 194°F (90°C) above 2000 RPM, the EMM:

If STBD cylinder head temperature is greater than 212°F (100°C) below 2000 RPM, or greater than 194°F (90°C) above 2000 RPM, the EMM:

*Throttle Position Sensor8

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 0.65 V when the key is turned to ON, the EMM:

If the outboard is started, the code is stored.

If the key ON voltage is greater than 0.78 V when the engine is started, speed is limited to idle.

If code 11 is present as both a Hard Fault and a Stored Fault, refer to Control Cable Installation on p. 53.

If the TPS or TPS circuit fails (less than 0.14 volts or greater than 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 reads above 4.85 volts, the EMM:

Crankshaft Position Sensor

The CPS is a magnetic device. It is mounted on the reed plate, next to the flywheel.

Ribs spaced on the flywheel mark crankshaft position. As the ribs pass the magnetic field of the CPS, an AC voltage signal is generated. The 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 intermit tent (10 instances), the EMM:

Approximate air gap between CPS and flywheel encoder ribs is .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.