We have a running gag here at the shop that when we sell a bike with Di2 we never see the customer again. The reason is because Di2 is simply reliable and the customer rarely comes back for service. In the event you do have issues we have diagnostic tools in house that can diagnose your Di2 issue. We are also near the west coast Shimano warehouse and typically can get replacement parts within 2 business days. If it’s a firmware update, a battery issue, or connection problem we can troubleshoot and fix your Di2 mountain or road bike.