I recently went to a Mercedes technical seminar. I'm not usually involved with modern Mercs so I thought it would be interesting. I feel a little naive now that even though I've heard of SCN coding before, I always thought it was more a myth that garages would tell the typical more-money-than-brains Mercedes owner. But no, its real!
The U.S. seems to be a bit better when it comes to consumer protection laws than Canada. See wikipedia regarding "Right to Repair" Motor Vehicle Owners' Right to Repair Act - Wikipedia, the free encyclopedia
The E in EPA after all stands for "Environment", they force Mercedes to use OBD for emissions yet are willing to let Mercedes destroy the used parts industry. I just don't get the logic here. One has to crush a perfectly salvageable car now because all the computers are loaded with cripplewear by greedy corporations. The recycle-ability factor is almost completely gone (except for scrap metal really). I refer to Mercedes, but it should be said that the entire German trio have their equivalents to SCN coding.
A modern Merc has a life-span of 5 to 10yrs. Never mind the cost of repair for a second, but once end-of-life'd by the manufacturer, proprietary protocols are rendered useless once faults occur. Given that the entire car is computerised now, it renders the entire car useless as well. Just look at the resale value of modern Mercs. A W220 S-Class can be had for under $10k. That's even more depreciation than the equivalent Jaguar XJ (X350) .
A Mercedes was once viewed as an investment. An investment like a house or plot of land, that one could pass down generation after generation. But now its just another gimmicky piece of technology that's completely useless without manufacturer support.
Now I'm sure some of you would have the view that this is an intrinsic problem associated with using sophisticated electronics/computers. But I argue it is not! Compare this to the 286 IBM compliant PC from the 1980s. Thirty years later and any competent engineering grad has the ability to reprogram it because it is built against a standard. One does not need support from IBM. Do you think 30yrs from now, one would be able to reprogram a W221 S-Class to accept an aftermarket transmission module?
Just as the aftermarket has reversed engineered mechanical parts and manufactured replacements, there is no reason why the aftermarket couldn't step up and make virgin/reprogrammable modules. And it is happening, but the reprogramming equipment is usually far out of reach from the individual. Keeping an Autologic unit up-to-date can easily run into 6 figures. And there is no guarantee it will even work.
I wonder what the guys at the Mercedes Classic Centre have to say. Is the w124 and w126 the last user serviceable Mercs?