The lateral acceleration error code is being generated by the ESP system, it has nothing to do with the TCM problem or the limp-home mode.

I don't think there is a 'dead TCM' code but even it there were you'd have to get in contact with the TCM to determine it its dead right? The fact that you can't establish communications with the TCM means one of two possibilities
1) the TCM is dead or the wiring to it is faulty. BTW the wires you repaired wouldn't stop a scan tool from communication with the TCM because on this transmission the TCM isn't housed in the transmission like the later 722.9 versions or 2) your scan tool isn't capable of communication with the TCM.

I'm not familiar with the icarsoft scan tool but in earlier years I used a Snap-on MT2500 and it would not always reliably communicate with all modules of the different cars I worked on. I do remember it being able to communicate with TCM's in W210 but not in a W202 even though they used the same 722.6 transmission. I also had troubles communication with airbag modules, sometimes it would work and sometimes it wouldn't work.

I would say its a good sign that the range recognition works when you plug in the TCM and it doesn't work with the TCM disconnected since transmission range information on this car is CAN related.

Have you ever used the your scan tool to access other MB TCM's? Do you know an independent shop in the area that has the real MB SDS scan tool? You're not going to fix this problem until you can establish communication with the TCM.

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