Sportsman says R no matter what gear its in

Hi guys new to the forum with a new to me 2003 Sportsman 600. First ATV after having motorcycles for years so trying to catch up on the learning curve.

First problem is over the weekend the gear indicated on the display started acting funny it wasn’t showing the right gear but performance wasn’t affected.
Come Monday the display was only showing R for reverse, and then the atv wouldn’t rev regularly. It was running cyclically, like it was being governed. I called a buddy who said it was acting like it was stuck in reverse, and I said well shoot it is displaying R so that makes sense. I held down the yellow button and sure as heck that got it to rev and drive normally.

It’s stuck in R no matter what gear I change to with the lever.

Anyone have any idea where I can start troubleshooting this?

Do these things have PDF manuals anywhere?

Thanks guys

I found this thread trying to find solutions but I don’t think I want to cut the purple wire. Sportsman Thinks It's Stuck In Reverse – Troubleshooting And Modifications – The ATV Zone