I had issues with my van while going through Valdosta Georgia, found a guy who works on Sprinters for FedEx etc.... He helped me get going, and suggested if I intend to keep doing long distance runs with my 2003, that I buy one of scanners available from harbor freight... the $89 model or thereabouts. He said it could reset stuff as well, but he said it would do what any mechanic would need while on the road.
He has a lot of unused parts, unknown to me, but he would relish the chance to get rid of this old inventory.
He also has about 3 or 4 of those models at his graveyard, having motor/trans problems, but with pretty nice bodies. I salvaged some of the parts, but although I wish for a new side door and back doors, I couldn't bring myself to swap those with my van because somebody should be buying those vans. I will post his contact number in the parts/for sale section of this forum.
Another thing I think I have learned is that the van doesn't shift well when the transmission oil is low. I have a leak, and will need to get it fixed. Maybe you need check tranny oil level??