[JD64]

Originally Posted by ember1205

My guess is that you also ended up removing the AFM actuators behind the secondary cats which means that you needed a tune to disable AFM. If so, you're already "tattooed" and GM knows you've monkeyed with it.

no afm on the ZL 1's

[MrChrisLS3]

Originally Posted by Mark R

I had my Borla cat-back installed at the dealer. The service advisor said it would not affect the warranty. I have had almost all my aftermarket stuff installed at the dealer - steering wheel, exhaust, and BMR suspension components. I figure they would not install them if they would void the warranty.

Most dealerships will do any work you pay them to do. Protecting your warranty is not their job when it comes to installing aftermarket parts for a customer. Things like an exhaust (catback) won't really effect warranty. That BMR suspension, gets into a grey area. If you run into a power steering issue, you might be on the hook for that.

Unless your steering wheel is a GM specified part, or meets all specs, if there is an issue with steering wheel controls, bluetooth, paddle shift, you might be on the hook for that.

Your vehicle warranty is not a single, cover all warranty. It is a combination of separate warranties. 3/36 basic warranty a.k.a. bumper to bumper covers pretty much everything like infotainment, interior/exterior suspension/handling parts, systems, assembly issues etc. Powertrain is a separate warranty covering engine and drive line, transmission, differentials. Then you have the emission warranty, covers catalytic converters, o2 sensors, and some fuel line issues. The corrosion warranty.

Touch that ECM and for the most part you are done. There is a flash counter with corresponding codes that have to match. Now, that said, warranty work is typically denied when GM wants to inspect either the car, or the ECM history. They may not always request this. If it is a recall, or common TSB issue, they may approve the warranty work w/o question. But, pretty much any major repair, internal engine failure, anything of that nature, yes, they'll check it.

The thought that the manufacturer must "prove" an aftermarket part must be the cause of failure comes from the Magnussen Moss Act. If you read the actual legislation, it prohibits companies from forcing customers to buy a certain brand of replacement parts. So, if you want to go with a Fram air filter, a Purolator oil filter, or Valvoline Oil, so long as they meet OEM specification, you're good. Anything that exceeds the manufacturer's parameter design or intent, and they are not obligated to cover.

[ember1205]

Originally Posted by arpad_m

The days of invisible computer module replacements are long gone, these systems aren't open and the necessary lockdown tech is now elementary knowledge. Without even knowing the details, I'm almost sure that while changes can be re-attributed as legitimate (say, dealer service or module upgrade/replacement), traces of any activity will certainly be preserved forever.

So it's not about whether a mod can be detected but how willing and accommodating the dealership performing a specific warranty repair is, and in some cases it's likely that even they can't do anything without incriminating themselves.

Often times, the warranty submission will require that the dealer read ECM information and provide it with the warranty request in order to get approved. So, GM has taken a lot of the decision-making away from the dealership itself in that regard since the option to refuse coverage is really GM's and not the dealership's.

[Techdude99]

Originally Posted by ember1205

Often times, the warranty submission will require that the dealer read ECM information and provide it with the warranty request in order to get approved. So, GM has taken a lot of the decision-making away from the dealership itself in that regard since the option to refuse coverage is really GM's and not the dealership's.

This is accurate. Additionally, the automaker's DPSM has some discretion if corporate denies a claim.