I had similar thing happen to my 2021 Sportsman 1000. Started it after it had sat for 3 months and got the check engine light. User's manual was worthless and said to take it to the dealership. So I walked into the service center and asked what it could be. I was told that it could be any of 100 different things but one of them was a low battery voltage. Since the reason I started it was to charge up the battery I thought that was probably the reason. Service manager said it should reset the check engine light after 3 or 4 times of using it.