YOU HAVE A RIGHT TO REPAIR AND REPLACE.

• Author: Mccullagh, Declan
• Position: TECHNOLOGY

RECENTLY I BEGAN to search for a used GMC Yukon SUV. My goal was to bolt on an aftermarket supercharger. It wasn't necessarily a sensible plan, but it did seem like a pretty cool idea. Thanks to a whopping 6.2-liter V8 engine, a Whipple supercharger would make that vehicle churn out nearly 600 horsepower of good ol' American tire-shredding glory.

I already knew about California's draconian emissions regulations, which view the prospect of modifying an internal combustion engine with such hostility that they must have been drafted by electric car impressario Elon Musk himself. And I was prepared to dodge and weave around those requirements. But first I needed to figure out whether that much aftermarket fury would violate General Motors' factory warranty.

As the Federal Trade Commission (FTC) explains on its website, for everything from trucks to toasters, the 1975 Magnuson-Moss Warranty Act "makes it illegal for companies to void your warranty or deny coverage under the warranty simply because you used an aftermarket or recycled part." Although as Road and Track puts it, if your newly upgraded engine sends too much power to the transmission and the transmission fails, the manufacturer "could deny the coverage on that repair."

Recently the fine folks at the FTC have decreed that the Magnuson-Moss Warranty Act also applies to electronics hardware--more precisely, to the warranties for electronics hardware. In April, the agency sent letters to Sony, Microsoft, Nintendo, Hyundai, HTC, and Asus warning the companies that they are now "on notice that violations of the Warranty and FTC Acts may result in legal action."

The FTC is complaining, among other things, about that little sticker on the back of the PlayStation 4 and similar devices threatening dire outcomes, such as "warranty void if removed." Those supposedly conflict with the Magnuson-Moss Warranty Act, which says that no manufacturer may "condition his written or implied warranty of such product" on using any specific repair service or any specific source for parts. Translation: If you upgrade your RAM or hard drive, or if you take your computer for some surgery at the shop around the corner rather than the Apple store, it doesn't automatically end your warranty.

Manufacturers would like you to believe otherwise, however. And it's easy to understand why they might creatively interpret the law as allowing them to slap on these stickers. If you open up an electronic device and touch a...