Diesel Particulate Filter and Diesel Emission Fluid

Can't speak for the big boys, but the Sprinter based vehicles are having some adventures with the DEF/DPF systems. Computers designed by MB shut down the engine when they get a code about the DEF, often a false code. Real pain in the U-No-Wat for those involved.

That said, mine hasn't been a problem (Yet!!), but I fill the DEF after every trip, rather than waiting for the signal message.