I purchased the 2002 C320 with it being stuck in 3rd gear. Scanned with foxwell NT510Elite and P2502, P2069 both from N15/3 ETC EGS control unit, and generic code P7030.
I replaced the 13 pin connector and conductor plate. Fluid was new as the previous owner had just did the same thing as the plate and 13 pin conn were new and he changed the ETC or TCU as the TCU had c240 written on the back of it like a salvage yard would do. No change still stuck in 3rd same codes. Replaced the TCU with used one from 2003 C320 cleared codes and was able to shift into 4th and 5th if i manually shifted. If I let it shift automatically it stuck in 3rd and wont allow me to manual shift unless I turn key off and back on. I tried to reprogram or reset TCU with Foxwell scanner but it locks up upon starting the adaption. Getting ready to just replace the tranny with one I got from a 2003 C230 had no issues at all. Would hate to do that if I dont absolutely have to. Thanks for any info suggestions ideas or any help.