The JetBlaster, built since 2022 around the 1049 cc three-cylinder TR-1 engine, has a control unit that watches close to 50 different faults. That sounds like a lot until you sort the codes into groups, and then it becomes a short list of places to start.
Which JetBlasters, which codes
Yamaha fits RiDE to the PRO and DLX versions of the JetBlaster, so only those can show the codes from the RiDE range (150 to 154 for the RPS, 157 to 164 for the SCU). A JetBlaster without RiDE won't have them, and the app only shows functions the ski actually has because it recognizes the model on its own. The M-JET Diagnostic supports the JetBlaster along with the VX, EX and SuperJet. For the model itself see JetBlaster diagnostics.
The numbers below come from the shared list of the newer control units. Which of them your ski really uses, and how they are numbered, can vary by generation and by source, so the wording in the app is what counts.
The groups, roughly
Engine position: 13 is the pulser coil and 24 the camshaft sensor. If the ski cranks but won't fire, these are the first lines to look at in the stored codes.
Air side: 23 for intake air temperature, 29 for intake pressure and 63 for the intake system, which reports irregular intake air.
Temperatures: 15 for engine temperature and 65 for the exhaust manifold water temperature. A TR-1 does not have a knock sensor, so code 17 isn't part of this engine family.
Throttle: the electronic throttle brings a whole block, 112 to 145 for the throttle valve drive, 124 to 128 for the throttle position sensors and 131 to 135 for the accelerator position sensors. The sensors come in pairs, which lets the control unit compare one against the other.
Switches and electrical: 47 for the slant switch, 51 for the throttle lever idle switch, 68 for the no-wake and cruise switch, and 19 for battery voltage.
Where I would look first
Start with battery voltage in the live data. A low supply makes the control unit log things that have little to do with the named part, and it takes a moment. After that read the fault memory and note every entry before clearing anything.
With the key on and the engine off, intake pressure and air pressure should read close to each other. A big gap points at a sensor or a leak in the intake side rather than at the engine.
For throttle complaints, open the live values and look at the paired signals: TPS1 and TPS2 on one side, APS1 and APS2 on the other. They should move together as you work the lever. One that jumps or lags behind its partner points to a connector or sensor, and that is more useful than the code number alone.
Then run the component tests. A three-cylinder ski has seven: three coils, three injectors and the fuel pump. Fuel system work needs good ventilation and no ignition sources nearby. Keep in mind that the pump test only shows the pump runs, not that it delivers enough.
Where the scan stops
Close to 50 monitored faults still leaves out compression loss, a damaged impeller, debris in the inlet and clogged cooling passages. When the codes are empty and the live values look normal, the problem is more likely mechanical, and a recorded test ride gives you something to compare against later.