So, Tesla's infamous inconsistency at work... I was told a while ago that they can't open up a PEM in the service dept, so have to swap the whole unit. The service person said he thought it had something to do with it not being designed with proper ESD protections for that sort of work. So, that's why the whole PEM swap, in my case, to fix the PEM fan connector issue (burned contacts), which are on an easily swapped sub-assembly. If the whole PEM is swapped, then the whole PEM gets a warranty. If they only warrant the part that was changed, then they must have a way to open up the PEM for surgery. The time it takes for the 3.0 upgrade is not long enough for shipping the PEM back to the factory for the rework.