As MBDOC said, the P0715 code usually means a bad speed sensor which is an integral part of the conductor plate above the valve body. It's about a $170 DIY part plus fluids and gaskets and you need to reset the ETC codes with a Star Diagnose System or equivalent to get the trans out of limp home mode. An OBD-II scanner can't do that level of reset.

__________________
Reid
Past ('59 220Sb, 2-'59 190's, '92 300D 2.5T)
Current
'04 E320 4Matic Wagon
'00 E320 4Matic Wagon