I don’t think YOU understand it. In the event that a claim is denied, you must be willing and able
To prove as the manufacturer/provider of the warranty that the cause of failure was directly caused by a non OEM part. Exhaust, intercooler etc could fall into that. That statute of the law is actually quite broad on what it does and doesn’t do. It’s simply there to protect the owner. Where are you getting your information from? If you haven’t had to deal with any of this first hand as a OE rep, writer, fixed ops manager or director, or are a lawyer that specializes in such cases I’ll just stop the argument with you now.
I have extensive field experience as both a technical expert and PMK. I’ve been deposed and I’ve been to court, including small claims. I’m very familiar with MM.
I don’t think we’re that far apart on this issue. What you’re stating is that in order for a manufacturer to void the warranty on a specific system or component due to a modification, there needs to be evidence that the modification contributed to the failure. That is true. Nobody is saying that an engine warranty should be cancelled because of a catback exhaust.
However, powertrain calibration changes are a different story. You are effectively replacing all of the safeguards, FMEM, fuel/air maps, boost limits, and spark knock strategies with an aftermarket calibration that has never been tested by the manufacturer.
Once you overwrite the factory calibration, any failures that can be attributed to the aftermarket tune are non-warrantable. This is true for all manufacturers. That includes things like cracked ring lands, broken connecting rods or crankshaft, blown head gaskets, turbocharger failure (overspeed), catalyst failure (cracked or efficiency DTCs), etc. It also includes damage to the transmission, transfer case, driveshaft, or axles that can be attributed to the increase in engine power/torque output.
None of this means you’re going to experience a failure due to an reputable aftermarket tune. We are not seeing a lot of tune induced failures on these engines; they are pretty stout. But it is something that everyone who is considering getting a tune should keep in mind. If a tune related failure does occur, regardless of how rare, it is important to understand the potential consequences.