Not enough information to even hazard a guess. The "check engine" light can come on for almost any problem. The "countdown-to-breakdown" can also occur for several reasons.
It's possible that you have multiple messages in the data display, but you're only seeing the most critical one. Try using the up and down buttons on the left side of the steering wheel to see if you can cycle through the messages. A message that's hidden by the countdown may tell the tale.
On Edit— You should be able to cycle through the message screens with the key in the "accessory" position so that you don't waste one of your few remaining starts just to read messages.
And don't delay in getting your van to a Sprinter dealer— when you get to "0" starts remaining, you're looking at getting it towed. That's a completely different problem all in itself, and I suggest that even though you have a few starts left, you should temporarily make a habit of parking it where a tow truck can get to the front end to hitch up; it's hard to manhandle a big van like that if it's not positioned for easy access by the tow truck.
Engineering: Finding complex solutions to simple problems you didn't even know you had.