Service Manual 5008330_55 HP MFE System Analysis [Diagnostic Procedures]

Inspect wiring and electrical connections. Disassemble and clean all corroded connections. Replace damaged wiring, connectors, or terminals. Repair any shorted electrical circuits.

• Refer to ELECTRICAL HARNESS CONNECTIONS on p. 113.
• Refer to WIRING DIAGRAM at the back of this manual.
• Refer to CONNECTOR SERVICING on p. 127.
Make sure all ground connections are clean and tight. Refer to GROUND CIRCUITS on p. 115

006489

1. Main engine harness ground

Inspect spark plugs for wear, oil fowling, or dam age. A rich or lean running condition or evidence of internal engine damage could be identified by the appearance of the spark plugs.

Check the fuse and the emergency stop switch lanyard.

Run the outboard to confirm actual symptoms before performing any unnecessary procedures. Inspection should include the following:

• Make sure the outboard can be cranked easily, with no mechanical binding.
• Check the EMM LED Indicators for system status information. Refer to EMM LED INDICA-TORS on p. 99.
• Check the Evinrude Diagnostics software Hard Faults and Stored Faults screens for current service codes before troubleshooting. Correct any problems and clear the codes FIRST. Refer to Stored Service Codes (Faults) on p. 88.

Stored Faults Review Screen 008098 Check the diagnostics software Profiles, History, and Persistent Faults screens for evidence of abnormal operation.

008088

Profiles Screen

Outboard cranks, will not start:

• Check emergency stop switch and lanyard
• Check powerhead mounted neutral switch
• Check the EMM LED Indicators for system status information. Refer to EMM LED INDICA-TORS on p. 99.
• Use the Evinrude Diagnostics software Stored Faults screen to check for current service codes. If there are multiple stored sensor codes, inspect all 5 V sensor circuits for broken or grounded wiring.
• Perform a Static Ignition test using Evinrude Diagnostics software and an inductive timing light. Refer to Static Ignition Test on p. 103.
• If ignition test indicates steady spark, refer to FUEL DELIVERY TESTS on p. 106.

Outboard runs, low on power, misfires:

• Check the EMM LED Indicators for system status information. Refer to EMM LED INDICATORS on p. 99.
• Use the Evinrude Diagnostics software Monitor screen to check system (55 V) and TPS volt ages. System voltage should be steady, and TPS voltage should be between 0.2 and 4.85 V.
• *IMPORTANT:** Use a digital multimeter to check voltage on external circuits only when necessary. All EMM output currents are DC current.
• Use the diagnostics software Dynamic Tests to isolate a faulty cylinder. See DYNAMIC TESTS on p. 98.

• Use an inductive timing light to check ignition and fuel injector circuits. Refer to Running Ignition Tests on p. 104 and Running Fuel System Tests on p. 107.

• Use the diagnostics software Fuel Control Adjustment test to help identify a cylinder that may be too rich or too lean. Refer to Fuel Control Adjustment
  on p. 98.
• Use an inductive amp meter to monitor injector circuit current. Compare readings of all circuits to identify possible failure.
• Check fuel quality and that fuel is present at injectors.
• Use the diagnostics software Logging function to record engine data as a problem is occurring.

008097

Logging Screen

• AFTER all the above inspections, if the cause of a running quality problem still cannot be identified, perform a compression test to check for internal powerhead damage.

IMPORTANT: Remove a cylinder head or disassemble the engine only as a last resort.