TL;DR: SCN Coding may be required for the 722.6 transmission's TCM if your car is a 2003 model year. 722.9 transmission is not required.

So, my TCM was a victim of an automated car wash flooding my air reservoir & running over to short it out. Look it up. It sucks.
I found a matched part number replacement for $149 on ebay. Most are $200 to $300. The replacement was from a 2003 S600.
I'd read in posts of similar issues that a matching part number TCM (sometimes referred to as TCU) would make everything better like nothing ever happened. In my case, that didn't happen.
I was still in limp-mode after the swap. While limp mode of my original TCM only let me to get to 2nd gear, I can now get to 3rd gear & 60 mph at 3k rpm. With the fried original, my limp mode would hit 4k rpm at 45 mph. My theory is that my S430 doesn't hit the top end of torque that limp mode allows from the S600. Another find is, as long as I keep the revs right for the corresponding gear, I can manually shift through 1st, 2nd & 3rd gears. Without downshifting while decelerating, it gets stuck in 3rd gear with a lazy take off from a stop. I'm hoping the shifting habit sticks with me after this is fixed because I appreciate how quickly this car gets off the line much more now.
I took my car to a local indy shop to have the TCU re-flashed to my car's VIN. Great guys at a very reputable shop but they didn't seem all that well versed on the STAR DAS stuff. They didn't get my VIN into the new part the first time. When they did finally get it entered, it then required SCN Coding. They had no idea how to do the SCN Coding.
The indy's head guy said he didn't understand why SCN Coding was required because that didn't come out until 2005. They didn't charge me for the attempt & sent me to the local dealer. I'm in a medium sized town & this sounds dumb but I couldn't get an appointment for 2 weeks. I still have a week left to wait. Back in Southern California, I could've had it done in a Burger King drive-thru for $6.50.
Now that all of that is out of the way, the reason for my post is my research kept coming to valve body replacement in 722.9, 7 speed transmission. Some posts specifically say that SCN Coding is only for that set up & not ever an issue with the 722.6 transmission.
Well, they are wrong. My indy shop was also wrong SCN Coding came out in 2003 when the TCU was still in the engine compartment for the 722.6 transmission. I have not been able to verify whether or not it's only on the face-lift version but SCN Coding is definitely required for my car.
I've found that one can extract the SCN Coding from the original part & enter it, offline, into the replacement part. Maybe I'll get a STAR DAS someday & this will seem like a waste of money but, today, it's another lesson in the wonderful world of the W220.
I'll update after I go to the dealer's service center. I'm expecting they're going to tell me I need to buy a $500 refurbished TCM & then the arguments begin.

 

There are a good number or articles that can be found regarding SCN Coding beginning with MY2003 but there was a SCN Coding recall for MY2003 - 2009 that seems pretty official to me.
http://www-odi.nhtsa.dot.gov/acms/cs...8v303-6143.pdf

Either way, my car is definitely a 2003 & the donor car for my replacement TCM is definitely a 2003.

 

UPDATE: TCM was flashed & SCN coded at the local dealer today. Everything is running great. $126 for an hour of labor.
The only bad part was the crappy, yet free car wash.

 

I own a 2003 W220 S430, and it has SCN coding yes it only for SRS Gateway and upper control panel, but it has it my 2006 W220 has SCN coding on all modules like newer ones