Probably the sensor and have one on order, but with the speedometer not working does this affect ADC or anything else?

 

Depending on year if the actual speedo goes bad it will effect the AWD. If it is just the hall effect senor it only effects the speed reading. It can also effect the overide in reverse if the speedo needle "bounces" and reads too high.....

 

Sorry, it is a 2008 800 HO and I believe it is the hall effect sensor. But you are right, I tried reverse and no limiter on it, but AWD and ADC still seem to be working.

 

I would be confident that it is just the sensor. replaced mine on my '03 600 about 3 months ago......

 

I had a 04 600 Sportsman that did the exact same thing it was a ground wire that came loose under the front hood. My advice to you is to not jump to conclusions and do your basic checks first!!!!!