Yamaha Outboard Diagnostics App

A fuel-injected Yamaha outboard reports a lot of its problems to the ECU first, often before the warning horn goes off or the engine pulls back the rpm. With M-JET DIAGNOSTIC you read that data yourself. You plug the dongle into the diagnostic connector on the engine, pair your phone over Bluetooth and open the app on iOS or Android. No laptop needed. Coverage includes 114 outboard entries with ECU generations from 2003 on, plus 37 WaveRunner models on the side.

What the app pulls from the ECU

• Read stored faults with the component, symptom and check steps in plain language instead of a bare number
• Clear the fault memory after the repair
• Live data, 14 to 65 values depending on the ECU, such as rpm, engine temperature, water pressure, oil pressure and battery voltage
• Actuator tests: fire ignition coils, injectors, the fuel pump, the ISC valve or the OCV one at a time
• Engine hours split into 7 rpm ranges, from under 1,000 up to 7,000 rpm
• Idle learning on many engines

Your ECU decides what your engine can do

An F25 has a different ECU than an F350, and you'll notice it in the number of values and tests. The app only ever shows the functions your engine's ECU actually supports. It runs in six languages: English, German, Spanish, French, Italian and Portuguese. Licenses cover 1, 3, 5 or an unlimited number of engines, which matters if you run twins or look after several boats.

Five power classes with their own pages

• F20 to F100: small and mid-size four-strokes with 18 to 30 live values and tests for the fuel pump, ISC valve, coils and injectors
• F115 to F150: four-cylinders, depending on generation with oil pressure, variable cam timing and electronic throttle
• F175 to F250: inline fours and V6 engines with up to 57 live values and individual tests for up to six cylinders
• F275 to F450: V6 and V8 up to the XTO class, up to 65 live values and 25 actuator tests
• HPDI Z series: the Z150 to Z200 direct-injected two-strokes, 34 live values including firing state per cylinder

Troubleshooting by symptom, plus guides

Most owners don't show up looking for a feature. They show up with a problem. The engine won't start, the horn beeps, the rpm drops into limp mode, the idle is rough, the temperature climbs or the oil pressure warning comes on. Each of those has its own page with the live values and stored faults that matter. On top of that there are guides for buying a used outboard, spring commissioning after winter storage and boats with two or more engines.

Where the electronics stop

The ECU only knows what a sensor or switch tells it. A worn impeller shows up at best indirectly through falling water pressure or rising temperature, and only on engines that measure those values. A thermostat stuck open will, on many engines, at most appear as an overcooling fault. Gear oil, anodes, the prop and compression are still hands-on checks. What the diagnostics do is tell you whether to look at the electrical side or the mechanical side.

Diagnostic functions

• Read Yamaha Outboard Fault Codes with Your Phone
• Clear Yamaha Outboard Fault Codes
• Yamaha Outboard Live Engine Data on Your Phone
• Test Yamaha Outboard Coils, Injectors and Fuel Pumps One at a Time
• Read Yamaha Outboard Engine Hours by RPM Range
• Yamaha Outboard Idle Learning via App
• Yamaha Outboard Diagnostic Tool Without a Laptop

Power classes and engines

• Yamaha F20 to F100 Diagnostics: Fault Memory, Live Data and Component Tests by App
• Yamaha F115, F130 and F150 Diagnostics by App: From Cable Control to Digital Shift
• Yamaha F175, F200, F225 and F250 Diagnostics: Inline Four and V6 by App
• Yamaha F300, F350 V8 and XTO F375 to F450 Diagnostics by App
• Yamaha HPDI Z150, Z175 and Z200 Diagnostics: Reading the Two-Stroke V6 by App

Troubleshooting by symptom and component

• Yamaha Outboard Won't Start: Checking Kill Switch, Shift, Pulser Coil and Battery
• Yamaha Outboard Warning Horn and Engine Warning: Finding the Cause by App
• Yamaha Outboard Limp Mode: Tracking Down Power Loss and RPM Limiting
• Yamaha Outboard Rough Idle or Stalling: Checking the ISC and Relearning Idle
• Yamaha Outboard Overheating: Check Cooling Water Pressure, Temperature and Thermo Switch
• Yamaha Outboard Oil Pressure Warning: Sensor, Wiring or Real Pressure Loss
• Water in Fuel Filter Warning on a Yamaha Outboard: How to Check It
• Yamaha Outboard Battery Voltage and Charging System Check
• Yamaha Outboard Electronic Throttle (ETV): Checking TPS and APS
• Yamaha Outboard Won't Shift: Remote Control, Shift Sensors and Neutral Detection
• Yamaha Outboard Knock Sensor: What the Fault Entry Means
• Yamaha Outboard Variable Cam Timing (VCT): OCV and Cam Position Sensor
• Yamaha Outboard Trim Not Working: Checking the PTT Sensor, Switch and Relays
• Coil or Injector: Testing Each Cylinder on a Yamaha Outboard

Guides

• How to Inspect a Used Yamaha Outboard Before You Buy
• Spring Commissioning a Yamaha Outboard After Winter Storage
• Diagnosing Yamaha Outboards on Twin and Multi-Engine Boats

Yamaha WaveRunner diagnostics

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.