Relatively "new to me" (10/2020) '97 E300D NA. 141K miles. Shifting issues with the 722.6. Purchased from original owner. Unfortunately, not much documented maint. history as they performed a lot of it (or, didn't) themselves.
As the cold weather began to take hold, noticed a delayed shift from 1st when the car wasn't up to operating temp. Checked the owners manual and it mentions the shift delay until the engine is warmed up. Ok, fine and good. Well, the situation got progressively worse.
Performed trans fluid/filter change (which was planned, anyway). Also plug adapter. The TCU had minor fluid ingress, just trace amounts (thank you lucky stars). Not positive, but it looked like the trans fluid had never been changed. Got everything back together, proper fluid level, etc. and no help for the delayed shifts.
However, when it would function properly, the trans felt MUCH better with the new fluid!
Started scouring the "forums" and saw mention of the indicator lights on the shift quadrant. The indicators for "D" and "4" were a little wonky and not always lit. Hadn't put 2 and 2 together at this point. Being new to this car, I assumed the lighted "PRND/4321" were simply to let you know what gear you were in while driving at night.....didn't know about the "TRRS".
So, to make a long story even longer.....if I play around with the shift lever, I can get the "D" to stay illuminated and the trans functions flawlessly. Same with "4". If, due to bumps/vibration, the shift lever moves slightly and the "D" light goes out, back to not shifting properly.
Looking for insight/advice before "biting the bullet" on this $100+ part. Seems like the cause of my issues, yes? Am I missing something? Is this control unit "plug and play"?
Is it relatively simple to install or will the gear selector unit explode, like an overwound clock, when I attempt to take it apart?
Sorry for the "novel", but realize background info is important when troubleshooting in cyberspace.
Thanks, in advance. This is a great forum and has been a lot of help to me on my "other" and first Benz, an '83 240D. I've had that car for about 3 years.