The check engine light is on, the WaveRunner is beeping, and you want to know what that number means. Yamaha fault codes are plain numbers, and that's exactly what makes them tricky: the same number can mean something different depending on the ECU generation. Here are eight codes WaveRunner riders search for a lot, with the meaning from our reference data.
Why the ECU generation matters
Our reference has its own K-Line code list for WaveRunners. Next to it sit the outboard list and Yamaha's CAN generation of ECUs, each with its own entries. Many numbers mean the same thing everywhere, some don't. Where there's a difference, the table calls it out. Why forums often give a different meaning than your app is covered in why fault codes on forums often read differently than in your app.
The most common Yamaha WaveRunner error codes at a glance
| Code | Meaning on WaveRunners (K-Line) | Difference on other generations |
|---|---|---|
| 13 | Pulser coil | none |
| 15 | Engine temperature sensor | none |
| 23 | Air temperature sensor | none |
| 24 | Cam position sensor | Outboard K-Line: TPS on some engines. CAN: cam position sensor (EX) |
| 29 | Air pressure sensor (intake pressure) | none |
| 47 | Slant detection switch (tip-over switch) | none |
| 51 | APS full close switch (closed throttle switch on the throttle lever sensor) | not listed on the CAN list |
| 163 | SCU (the RiDE control unit) | CAN: RC system |
What's usually behind these codes
13, pulser coil: without a clean signal, the ECU doesn't know when to fire and inject. Hard starts and misfires fit the picture. Check the connector and wiring first, then the sensor.
15 and 23, temperature sensors: more often a connector, a wire or the sensor itself than real overheating. A good test: after the ski has sat for a while, engine temperature and intake air temperature in live data should be close to the outside temperature.
24, cam position sensor: if the engine is slow to start or runs rough, the connector and harness are the first suspects, the sensor comes after that.
29, intake pressure: typical causes are a leaking hose, moisture in the connector or a dirty sensor. With the key on and the engine off, the reading should be close to ambient pressure.
47, tip-over switch: it shuts the engine off after a rollover, which is how it's supposed to work. If the code sticks, check the connector and how the switch is mounted. More in tip-over switch: why the engine dies after a rollover and what code 47 means.
51, closed throttle switch: often corrosion on the throttle lever sensor or a wire that chafes when you steer.
163, SCU: affects models with RiDE. What 157, 158 and 163 mean and when SCU initial learning comes in is covered in Yamaha WaveRunner codes 157, 158 and 163.
A check order that works almost every time
- Read and write down every code, with description and status, before you clear anything.
- Check the battery: a weak battery likes to set several codes at once.
- Unplug the sensor connector, look for salt and corrosion, clean it and plug it back in firmly.
- Follow the harness, especially where it moves or where water sits.
- Clear, then test ride with recording on: if the code comes right back, the fault is permanent. If it only shows up under load, the recorded test run tells you when.
- Only then replace the part.
Read and clear the codes with the app
With M-JET DIAGNOSTIC for Yamaha, you plug in the dongle, open the app and see every code in plain language, with possible causes and concrete check and repair steps. No laptop needed. Depending on the model, you also get up to 34 live values, such as rpm, engine and water temperature, intake pressure, intake air temperature, battery voltage and throttle position, and you can record test runs. Once the repair is done, you clear the fault memory right in the app. For a step by step look at reading codes, see reading Yamaha WaveRunner fault codes.
When to see a shop
If a code comes back active even with clean connectors, good wiring and a charged battery, if several engine codes are stored at the same time, or if the engine clearly sounds different than usual, it's time for a shop. The same goes for a temperature code that shows up together with real overheating symptoms.
Frequently asked questions
Is there a complete list of all WaveRunner error codes here?
No, on purpose. Many codes mean different things depending on the generation, and a long list is more likely to mislead you. The app shows the description that matches your ECU.
Why does my forum explain the code differently?
Usually the explanation comes from a different ECU generation or from an outboard. Code 24 is a good example: the cam position sensor on a WaveRunner, the throttle position sensor on some outboards.
Does the check engine light go out after clearing?
Yes, as long as the fault is no longer active. If the cause is still there, the ECU sets the code again and the light comes back.
