AMS-W202

I've been having an issue with the transmission in my 1997 C230 (W202) with a 722.6. It's stuck in first gear. Some have said it's not stuck in first, it's in limp mode but I've experienced limp mode multiple times in the years I've had the car and this doesn't feel like it. Everything sounds and feels normal until I see the RPMs rising further and further. I've tried switching from S to W but nothing changes. Conductor plate and fluid have been ruled out and I'm no longer receiving transmission codes since changing the TCM. I live on the coast and there was a saltwater flood last year although I have not seen any indicators that water got into the transmission itself. I drove the car the next day and it was showing a TCM code and typical TCM symptoms. When I took it on the road after the flood, I could tell it was the TCM before I even checked the codes. I replaced the TCM and the TCM code went away but it didn't resolve the problem. Check engine light is on but it's P0410 Admittedly, the car has spent a lot of time sitting since then while I've been dealing with my house.

In other places I've asked, shifter seems to be the most popular suggestion and that's probably my next approach. My diagnostic options are limited considering the fact that there are so few places in my area that are willing to touch a Mercedes. It's also tourist season and I'm reluctant to take the car on the main roads.

I want a somewhat definitive diagnosis before resorting to a rebuild. If its determined that I need a new transmission, I'm opting for a manual swap which is something I've considered in the past.