So the big news Wednesday was that Ford issued a TSB telling its dealers how to check for aftermarket parts and/or PCM calibrations on 2011+ Mustangs. Every time something like this comes to light (and this is far from the first such bulletin from Ford or, for that matter, other OEMs), the various and sundry interweb fora erupt in dismay, and folks start trotting out the Magnuson-Moss Warranty Act of 1975 and proclaiming “Ford can’t do that!”
Yes, Ford (or any other auto manufacturer) can do that. Magnuson-Moss was never intended to encompass modifications from factory specification. If you choose to modify your under-warranty automobile, you pays your moneys and you takes your chances. Muck with the PCM cal and you can expect the powertrain warranty to be void. I don’t know why people are surprised by this.