Summit 850 keeps beeping 'check key' when I start the sled in the mornings . Even after changing to the spare tether and restarting.Once it fully warms up ,it's all good. No power accessories on the sled. I find out that there is a service bulletin about this RF interference and should install a ferrite magnet from BRP.. Dealer says this is not covered by warranty ? WTF! Seems like our S+M Edmonton Salesman is no longer with them, and no longer get any discount on parts either.