Magnuson-Moss Warranty Act

[More Power]

Back in 1975, the MM warranty act was written and signed into law primarily to define all manner of warranties and to create a standardized language for all US manufacturers to follow - whether they be an auto manufacturer or a kitchen appliance manufacturer. Included, as a minor point, was language that helped to protect aftermarket auto parts manufacturers with regard to auto manufacturer warranties. Before MM, Chevy/Ford/Dodge could deny your vehicle warranty after installing just about any product, no matter whether that part had been a factor in a covered failure.

After MM, auto dealers/manufacturers were/are (theoretically) required to prove that a modification either contributed to or caused a covered failure - before denying coverage.

Warranty disputes are generally handled through arbitration, where a fair-minded third-party hears both sides (usually someone familiar with the automotive and related industry), then arrives at an equitable settlement. It's worth noting that the auto manufacturers win approximately 90% of these cases, cuz it's really hard to prove that an aftermarket part didn't "contribute" in some way to the failure. What this really means is that the vehicle owner has the burden of proof. Some of the larger aftermarket companies (i.e. Banks) have provided engineering support in arbitration cases involving their products. This is a big help in resolving a dispute in the vehicle owner's favor.

That said, GM has begun selling performance exhaust systems for their diesel pickups, and the last time I checked, they sold performance air intake kits for quite a few of their gas powered vehicles. These are (or can be) installed at the dealership, and your vehicle warranty will cover the new parts as though they came on the truck from the factory.

To take this logic a step further, you shouldn't have a vehicle warranty problem following the installation of an aftermarket product that doesn't alter boost pressure or fueling. Products that passively make the engine more efficient, like exhaust or intake systems, shouldn't affect your warranty (except for oil contamination of the MAF sensor).

Now, everyone should know that any active power modification can put your warranty at risk. Active power mods would include performance products like chips, modules, programmers or tuning. How strictly this might be enforced depends on your local dealer's interpretation of GM's official warranty policy. Some dealers are lenient and some are "letter of the law" types. We here at The Diesel Page suggest you discover which type your dealer is by talking to your dealer service manager before installing any active mod.

Check with www.sema.org for more information concerning MM and to learn more about your rights when installing aftermarket parts.

Jim

[killerbee]

MM is so frequently misquoted as some safety net for doing anything you want to a vehicle.

Paraphrasing another explicit clause that is important, is that if the manufacturer requires the use of a singular component, like a specific motor oil, then that component must be supplied for free.

Hope I didn't misquote it.

[More Power]

We get questions all the time asking whether a particular power or drivetrain mod would void a warranty. The easy answer involves a role reversal.

If you are the manufacturer, and responsible for all of the costs associated with the vehicle warranty, would you consider it reasonable to cover the warranty if a customer installed an "X" modification?

If a reasonable person could honestly answer yes to that question, then that modification might not jeopardize a warranty.

Jim

[Dakster]

MM is so frequently misquoted as some safety net for doing anything you want to a vehicle.

Paraphrasing another explicit clause that is important, is that if the manufacturer requires the use of a singular component, like a specific motor oil, then that component must be supplied for free.

Hope I didn't misquote it.

Interesting... The fact that Honda has only ONE transmission fluid that you can use and VW has only ONE Motor oil that you can use, means they must supply those for free???

I need to get a copy of the MM Act so I can bring it with me to the dealer and demand my "Free" oil.

I agree that everyone thinks MM is the big safety net.

[killerbee]

Interesting... The fact that Honda has only ONE transmission fluid that you can use and VW has only ONE Motor oil that you can use, means they must supply those for free???

I need to get a copy of the MM Act so I can bring it with me to the dealer and demand my "Free" oil.

I agree that everyone thinks MM is the big safety net.

not exactly. It is with respect to availability of an aftermarket alternative. A manufacture can force you to use only their parts BUT if they do they, the manufacture, must supply it to you free of charge and free of any labor cost IIRC.

However, don't get excited yet. There is a big difference between what a piece of paper says, and what you will get in reality. The MM is a legal tool for attorneys and pro se complainants. Few people are ever successful using it across the counter (this will get a good laugh however). You will need it for scheduled arbitration or the expensive civil hearing.

IOW, for most people, the MM legislation is worthless. IMO

More effective, is a good sensible tactful argument, with a tasteful personality, the old flies with honey thing. Especially when the reality involves a $5000 retainer, time off from work, etc

[More Power]

I received a message from a fellow recently who bought a new LMM GMC. He soon installed a tuner which promptly plugged the Diesel Particulate Filter with soot. He removed the tuner, took the truck to the dealer, who installed a new DPF under warranty.....

Then, he re-installed the tuner, which resulted in another plugged DPF. I've heard that the DPF is a $1000 part. I don't think this is an MM nor a GM warranty situation...

Perhaps the tuner manufacturer should cover the warranty for a plugged DPF.

Jim

[murphyslaw]

no the dealer should not be responsible for this consumers deliberate act in modifying the engine systems(with the "chip") of the vehicle in a way that has caused undue part/component failure.

[FBJR]

Interesting... The fact that Honda has only ONE transmission fluid that you can use and VW has only ONE Motor oil that you can use, means they must supply those for free???

I need to get a copy of the MM Act so I can bring it with me to the dealer and demand my "Free" oil.

I agree that everyone thinks MM is the big safety net.

And how many of us really only change the oil when recommended?

We do it much more often right, so I doubt you would get free oil before the recommended change schedule.


I agree, the PT should not have been changed under warranty.