I plugged my Superchips Cortex up to the SUT, it connected to the PCM and pulled down current configuration only to alert me that the installed configuration is NOT a stock file. It then gave me a T-43 error code and said to contact Superchips support. The Cortex will NOT attempt to overwrite the foreign tune...makes sense I suppose...don't wanna get a bunch of random configs going on in that fancy computer brain.
Superchips support indicated that the vehicle must have been tuned by the previous owner; and further clarified that the "T" in the error code stood for "transmission." They instructed me to have the dealer re-flash the PCM with "as built data" to wipe out the current configuration. Seems simple enough, right?!
Well maybe not...most of the GM dealers that I initially spoke with made this out to be a huge, "iffy" scenario. "Well, we might not be able to re-flash the PCM...it depends on the tuner that was used...blah blah blah;" which got me worried that I might be stuck with this unknown tune and/or that I'd have to buy a new PCM to get back to stock. The truck was originally sold in California and god knows what those EPA hippies out there might have done to it.
But then I called my old, trusted HUMMER dealer (now a Chevrolet and fleet truck dealer) and they simply said "just bring it in an drop it off."
So...is it "iffy" and difficult, or is it a simple fix? I guess I'll find out shortly. As it stands now I've got an appointment to drop the truck off Saturday morning for a stock re-flash of the PCM, but thought I'd post a thread about this in the event that someone else runs into a similar issue and similar alarmist service departments.
More to come.