[maccecht]

There are two sensors on the CVT one at the front one at the rear, Rear one you can't remove without sliding the CVT off front one you can. Take it out and clean it might work if not likely need a new one. The electrical connection is on top of the engine just in front of the seat. Need to remove the engine cover and you should reach it. Clean it first and see how you go

 

[maccecht]

So where is this mysterious dealer plug under the seat, I have a 2017 650 burg

Under the air filter cover.