Axis Wakeboard Boat Forum

I have an 2016 Axis A24 boat that I love to death but it will be the death of me. Last year I spent $5000 fixing my boat where the technician could not figure it out and finally replaced the wiring harness after replacing the ECM which they said was still bad even though it didn't fix it as well as a sensor, and then eventually the harness. It ran great all this year until the end of the season on the last run for the season and I get a service required warning and then eventually an engine derate. No codes were detected, it turned on the VIL engine light which no one knows about and I could clear it pushing the button on the dash. The boat would work fine for about 1 minute or less, I would then get the service required warning and then the derate. I did look at the gauges to see if there was anything unusual. I noticed the water temp was all over the place from 150 to 200 then back down but it was constantly fluctuating. I pulled it off the lake, disconnected the batteries, changed the water thermostat which was really bad and changed the impeller because it had been two years. It looked fine but I changed it anyway, good insurance. Took the boat back out. The water temp worked perfect at 170 - 177 and never fluctuated beyond that. The boat worked great for the first half hour so I started to surf. Surfed for about 15 minutes then the service required warning came on and the boat immediately derated. There was never a code. If you turned the batteries off the VIL light would go out but come back on once the service required warning came on. I do not want to take it back to the dealer. I do not trust them. Ideas please. How do I read VIL (Not MIL) codes without a reader. I'm assuming that's why it doesn't show on the dash diagnostics because it is proprietary? Please give me some ideas.