Yamaha EX: Engine Warning Lit, but No Code to Be Found

This question comes up often in forums: the engine warning is on but nobody finds a code. Usually the fault is sporadic or only stored. M-JET DIAGNOSTIC shows both.

What you check

• Fault memory: view active and stored entries separately
• Live data at standstill: temperatures, voltage, switch status
• Data logger on a test ride until the warning returns
• Check connectors for moisture and corrosion

Narrowing down sporadic faults

A sensor that only drops out now and then does not show at standstill. The data logger records which value tips right before the warning, for example a short voltage dip or a jumping temperature value. That is often a contact problem. Observe whether the display resets by itself after switching off and restarting, and read the memory then too. It is reported in forums that the display can reset itself after several start-stop cycles. A fault that only occurs occasionally nevertheless remains a case for memory and data logger.

Related topics

• Yamaha EX: Overheat Warning, Then Limp Mode: Cavitation or Sensor?
• Yamaha EX Beeps While Riding: Oil Pressure, Temperature or Battery?
• Yamaha WaveRunner Engine Warning Lit
• Diagnostics and fault codes for your Yamaha model
• All Yamaha WaveRunner diagnostics topics

Everything runs via app over Bluetooth, for Yamaha WaveRunners from model year 2002 to today. Learn more about the M-JET DIAGNOSTIC for Yamaha WaveRunner.