Clear Yamaha Outboard Fault Codes

You drained the water separator or cleaned the connector on the thermo sensor, and the fault is still sitting in memory. Stored faults stay in the ECU until somebody clears them. With M-JET DIAGNOSTIC you do that yourself from the app, once you've fixed the cause.

The order that works

• Read the fault memory and write down or screenshot every entry
• Fix the cause: drain the filter, clean the connector, repair the wire or replace the sensor
• Clear the memory in the app
• Run the engine up to temperature in the water, ideally with a short run under load
• Read it again. If it's empty, you're done

When the fault comes right back

If an entry reappears right after clearing, the fault is still present. The ECU keeps monitoring its sensors and logs the fault again as soon as it happens. You see this a lot with a water detection switch in the fuel filter that has a corroded plug, or a lanyard that isn't seated properly. Some faults only show under certain conditions, a thermo switch only once the engine is warm, a weak battery only while cranking. That's why the test run is part of the repair.

Entries without a real fault

Some entries get logged without anything being broken. An engine shut-off switch entry because someone pulled the lanyard with the engine running, or a voltage dip because the battery went flat over the winter. Write those down, clear them and watch whether they return. For entries on the oil pressure sensor, knock sensor or thermo switch, work through the check steps first before you clear anything.

Clearing doesn't fix anything

Clearing the memory right before selling a boat or dropping it at a shop mostly wipes out the clues that would help find the problem. The fault will log again the next time it happens anyway. So always read first and save what's in there. If the engine goes to a shop, a screenshot of the fault memory saves them time. An engine that throws the same warning shortly after being cleared needs a proper search, not another clear.

Check the live data afterward

After clearing, live data tells you whether the affected value now makes sense. After a battery swap, voltage with the engine running should be higher than at rest, otherwise the charging system isn't doing its job. After replacing the intake air temperature sensor, a cold engine should read roughly the ambient temperature. After work on the shift linkage, the shift position switch should read differently in neutral than in forward or reverse. Only when the value and the memory both check out is the job finished. Which faults and values you see depends on your engine's ECU.

Related topics

• Read Yamaha Outboard Fault Codes with Your Phone
• Yamaha Outboard Warning Horn and Engine Warning: Finding the Cause by App
• Yamaha Outboard Live Engine Data on Your Phone
• All Yamaha outboard diagnostics topics

Everything runs via app over Bluetooth, for Yamaha outboards with control unit generations from 2003. Learn more about the M-JET DIAGNOSTIC for Yamaha WaveRunner & Outboard.