I've got 2 1994 E420s. One of them gets the occasional error code 26. I usually ignore it and just clear the code. The car in question has never shifted gears exactly like the other. Not smooth and linear as it should be. More like kinda sharp, revvey, jolty all at low rpms. When you gun it all works as it should.

anywho, I thinking that all the weird tranny activity could be due to a need to change the tranny oil and filter. But I guess I would have the shop test the LH-SFI module.

BUT to the thread topic, would it be okay to take the module out of the good 420 and put it in the "bad" 420 without problems? If there is a difference would I be able to notice it immediate, or is the module such that it has to learn and therefore I wouldn’t notice a difference until some time and mileage has passed.