<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SledgeHummer:
Well I cant say about my H3, haven't had any mods done on it, but I can speak for my Chevy Blazer's dealer workshop (still is a GM dealer)
First you're right they tend to blame anything and everything on a simple cellphone plastic holder on your dashboard
. they once blamed the AC compressor failure on my K&N kit regardless if the K&N documentation says it doesn't void your warranty. which is ridiculous, one has nothing to do with the other.
Anyway, I too changed the programming on the PCM only, with a Hypertech Powerprogrammer III, and everytime I take it for service, I simply make sure it's noted on the service card that the chip is re-programmed.
If anything they are working on (fixing) is controlled by a module (PCM or BCM) they will ask you to come in and change it back because their equipment will not function on a re-programmed chip. it will give them an error message sometime on THEIR equipment.
Conclusion : if it's regular service, you dont have to change it back. if they are fixing something and need to access one of the Modules, you'll HAVE to change it back.
Whatever you do, don't make the mistake my friend did on his 2001 Jeep wrangler, he tried to "hide" the fact he re-programmed his chip, dealer tried to access it, got an error message, went ahead and changed the entire PCM module and CHARGED him for it (part & Labor) heheheheh. Always make sure you mentioned the programming issue on the vehicle service card while delivering your vehicle for service.
SledgeHummer </div></BLOCKQUOTE>
Commonality of reprogramming the BCM or PCM is dependant upon the vehicle. As for a radio, I would not switch out the head unit, I would just tell them about the fuse, and you should remove it when taking it in for service.
As for reprogramming a computer with an aftermarket program, it depends on the vehicle and program. My vettes have all been reprogrammed, and the Tech 2 will write to them with a new GM program without notice. Everytime there was a factory reprogram for my Vette, I would just grab a Tech 2 at work, and do the program myself, then re-install my "special" program. In some cases, I had to have my "special" program tweaked for the new GM program.
If a tech took a look at the program parameters you installed, he/she would notice a difference; however, if a vehicle comes in for a re-flash, he will just re-flash the computer and not even look at the parameters.
Personally, I would never tell a service advisor that I had a PCM reprogrammed. One example would be I reprogram to change the shift pressures and scheduling on an auto trans, and the trans requires repair. They might be able to safely say the changes in the pressure and shift schedules destroyed the trans. Not saying GM would win in court or with the BBB, but why put yourself through the hassle.