The Magnuson-Moss Act protects the owner of a vehicle under warranty. In a nut shell, it says that a dealer/manufacturer has to prove that a modification caused a malfunction or breakage. Your warranty does not become null and void because you changed mufflers or changed plug wires.
This is absolutely true, but we all know (I hope) that if a warranty claim is denied by GM or a representative of GM due to a speculated or suspected mod, this may end up in court, or at the least in arbitration... This whole time, av sits or owner pays for repair with the hopes of getting re-imbursed...
So, if you have done a mod that may cause the dealership to take a hard stand in the face of a related component faiure (proof or no proof at the time), be prepared to fork out the duckets with or without Magnuson/Moss in hand ...
To also get technical, if they say an aftermarket part caused the failure, and refuse release of your vehicle until invoice is paid, you can argue all you want about proof... How do you expect they prove anything on the spot? ... It will end up in argument, they say, "ya aint getting your truck until bill is paid" (I think this is referred to as a Mechanic's Lein) ... You pull out gold card, and battle it out later... Again, through one of the avenues I mention above... So let's say it goes to court... Hmmm...
You show up in court with documentation in hand, and GM rep shows with corporate attorney... (Trust me, the aftermarket manufacturer who made the part in question will not go on record in writing or in person, so all you say about the product will be heresay...You are now a risk to them; they ain't goin' on record! ... Hey, hey, GM is involved now... They know you're gonna lose, and then blame it on them, and it is worse for them if they went on record, then you could sue them, using their own statements! ) ... You speak, they speak, Judge believes professional big company jargon no matter what Magnuson/Moss says... Your fluglebinder hoopdie doo MOD ran the motor lean, and you fried valves because of it... Your warranty claim will not be honored, because the Judge won't rule for you... And all future emissions warranty components are in question... So, after time spent, money spent on your attorney if you hire one, what's PROOF? ... It aint written this way, but if GM says NO, trust me they'll make their proof believeable to whomever presides that day ...
This is a pretty far fetched circumstance, and the Dealership will normally bend over backwards for the consumer, but don't think because SEMA, and Magnuson/Moss has spoken, that you're 100% safe...
It happened to me... I went down this road, and over a $130 MAF, it wasn't worth putting the rest of my warranty in jeopardy, and pulling out the swords... I just shut my mouth and bought the parts like I was asked... I mentioned SEMA, and they laughed... I called SEMA, and they said I should file a complaint which could take 2 to 3 weeks to review ...
It's not like having an atty on retainer... You have recourse if you've been wronged, but it can be articulated in court that ANY powertrain mod that interferes with the PCM will have caused the problem... The Judge aint a gearhead...
Please all, realize that this is worst worst worst case scenario, and I have only had one issue in the past 6 or 7 vehicles I've had... This is very far from the norm... And it comes down to dollars... If you have gone through 2 or 3 O2 sensors, and you have headers, DirectHits, other than oem plugs, and a cat back, your dealer might start to question...
So, the thread is not "will this void a warranty" they can't void the whole warranty for a basic mod... It just doesn't happen... But when I hear people bring up the Magnuson/Moss rule, and SEMA, as if they are some deterrent to GM and warranty denial, I gotta speak out... It just doesn't work that way...
Again, it depends on what your dealership can run through the system without alerting anyone beyond... Another thing that has been happening recently... Some dealerships have had problems with service writers writing up girlfriends, and families repairs on other customer's VIN as they are out of warranty... Joe Smith may have never had his tranny replaced, but he did according to the fraud commiting writer across the country... This has caused some dealerships to come under warranty charge spot checks... So, if your VIN has a large dollar amount of service written on it, it is possible your dealer might get a phone call from an auditor about your truck just to check if everything is kosher ... This situation alone has caused service centers to really watch what they say ok to and not ok to ... So, ever more, dealerships are getting stricter and stricter as GM is watching more and more what goes on...
11H