Its been recently reported that:

BMW is now selling subscriptions for heated seats in a number of countries — the latest example of the company’s adoption of microtransactions for high-end car features.

A monthly subscription to heat your BMW’s front seats costs roughly $18, with options to subscribe for a year ($180), three years ($300), or pay for “unlimited” access for $415.

Heated seats only use simple electronics so you could presumably open up the car's panel and rewire the cables to bypass the computer entirely, making it possible to trigger the seat heater using a physical button. There would be zero software modifications, so presumably you won't be violating any copyright laws.

Would it be legal to do this in the US?

  • 4
    Why do you think it might be illegal? You aren't tampering with the car's safety features. Commented Jul 14, 2022 at 1:54
  • 14
    @MichaelHall trying to figure out if there's any limits on what you can do with a physical thing you own Commented Jul 14, 2022 at 2:04
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    There may be some fuzzy precedent on this. I recall a (probably ongoing) issue where John Deere prohibits customers from even just repairing their own equipment under guise of copyright. So much so that farmers were lobbying to exempt farm equipment from DMCA. Commented Jul 14, 2022 at 11:06
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    Not just BMW. There's a motorcycle safety vest that puts buyer's life under a subscription plan Commented Jul 14, 2022 at 13:42
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    @user2979044 and when that didn't work, the farmers turned to Ukrainian hackers and firmware.
    – BruceWayne
    Commented Jul 14, 2022 at 18:59

5 Answers 5


There are limits to what you are allowed to modify on your car. Federal safety regulations require certain features to be installed by the manufacturer, and to be maintained by the owner in a state that they remain functional. Besides obvious things like brakes, you need working headlights, turn signals, bumpers, wipers, etc.

Heated seats is an option. A luxury convenience feature. Most cars don't have heated seats. If you had heated seats, but left them off or the switch broke and they weren't working, there would be no reason for the State Patrol to care one bit that your rump was a bit chilly.

So, the state doesn't care enough make it illegal to have heated seats or not. It is entirely your choice.

The question then becomes, does the state have any reason to care whether you have a manual switch to turn them on or off, or use a special software code to enable the feature? Logic dictates that if they don't care whether or not you have the feature, and don't care if you are using it or not, they would have not reason to care about the particular method you use to turn it on or off...

Therefore the only real question is does BMW care? They might, if you came up with a method of enabling heat without a subscription and it became known to them. Especially if you made money publishing a how-to guide that cost them potential revenue. But that would be a civil, rather than a criminal matter.

To me this action would be equivalent to buying a burger at a place that charges $.25 for a packet of ketchup, and instead using your own ketchup. It's your burger, and your ketchup, do what you want!

Based on discussion on the other answer, as well as a suggestion in comments, I would like to briefly address (my opinion) on the applicability of the Digital Millenium Copyright Act (DCMA) of 1998.

I actually just looked up this act, and have only a layman's understanding of copyright law, but there is a basic element that needs to be met for a violation to occur: The copyrighted material must be reproduced, altered, repurposed, and distributed in some manner. Private avoidance or selective non-use of a digital feature would not seem to rise to that level.

I touched on this above when I alluded to publishing a written hack. It would probably also apply if you offered code that would bypass a feature, or to a car tuner offering to enable the feature for a fee. If there is a commercial benefit, there is a potential "victim", and a copyright issue.

However, even code is questionable... There are many examples of companies offering aftermarket Engine Control Module code to enhance performance or improve gas mileage. Of course a manufacturer could always challenge a commercial competitor, but lawsuits cause money and create publicity - positive and negative. About the only "free" enforcement tool a manufacturer has is to not honor the warranty on any owner altered parts.

Of note is the fact that seat heating elements are not digital, copyrighted, or otherwise protected work. The digital intellectual property that MIGHT potentially be at the center of a copyright controversy is the function of the pay system and the processing of an access code that unlocks a relay. What that relay sends electrical current to is really immaterial. It could be your stereo, it could be the airbag...

One person snipping and splicing wire to avoid the IP "brain" and install a simple on/off switch or rheostat for personal use of seat heat should not be violation of any digital copyright law.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Dale M
    Commented Jul 18, 2022 at 5:58

One sense in which it might be illegal is, it may be a violation of copyright law by circumventing access-protection measures. You stipulate that this can be done without modifying the software, but this is not what the relevant law prohibits. 17 USC 1201 forbids you to "circumvent a technological measure that effectively controls access to a work protected under this title". That means, if the feature can be turned on by re-wiring, so that you can "connect" the control program bypassing the software gate-keeper with a simple wire, that violates the law.

A second sense in which it might be "illegal" is that it might violate a contractual term, thereby invalidating the warranty. When people ask about things being "illegal" here, they often mean "can I do this under the terms of the contract". You would therefore have to look at the terms of the contract (and since this feature does not exist in the US, this is a hypothetical exercise – they would write the contract for the US to comply with US law).

The third common sense of "illegal" would be that the company might sue you for damages. That seems rather unlikely. You have no obligation to "do what they tell you to" (in case they tell you "don't hook wire A to tab B"), though it can have consequences for the warranty – but they haven't been harmed by you servicing your own vehicle.

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Dale M
    Commented Jul 15, 2022 at 22:17

I assume there is a contract. You used to be able to buy the car with or without heated seats. Now you are in a better position as a consumer: You can buy the car without heated seats and change your mind at any time. If you sell your used car, the new owner can add the heated seats. Or remove them and get some money back.

There is a financial cost for BMW: The cost of adding a deactivated seat, at cost, with zero profits. The benefit: They don't have to build two different cars, and they make money when users who bought the cheaper car without heated seats to change their minds. Owners will find it easier to sell used cars. Overall I would think the system is beneficial.

Now if customers can buy with deactivated seats and activate them, and this is legal and free, then BMW will obviously lose money and stop doing this. So the benefits for everyone disappear. That's one of the important uses of contracts, to enforce behaviour that is beneficial for everyone.

The technical side should really be irrelevant. And hiding behind copyright or similar is nonsense. You sign a contract, or you don't.

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    The term purchase "contract" has come up a lot. Typically they document the model, price, financing and warranty terms, but not much else other than some fine print that most people skim over... Inserting language with the intent to "enforce behavior" after the sale probably wouldn't stand up in a US court. Commented Jul 15, 2022 at 16:11
  • This is a good point: if it is "ok" for people to buy the not-activated-heated-seats for a lower price, and then activate them "for free", this arguably decreases the manufacturer's motivation to make the same car for both activated and unactivated... so will possibly charge more for both, because of the need/motivation to do things differently. :) Commented Jul 15, 2022 at 19:23
  • @paulgarrett: A court might well turn around and say "That's BMW's problem. If they want to prevent people from modifying their cars, they can persuade Congress to pass a law to that effect. Otherwise, it's not something you can just stick into a contract of adhesion and expect the court to enforce."
    – Kevin
    Commented Jul 15, 2022 at 23:59
  • @Kevin, right... and it occurred to me that BMW could/might stop making just one kind of car, with/without heated seats enabled, ... instead making two types of cars... but/and then it would cost them more to play that game, and they'd surely pass the cost along to the consumer. Not that I'm defending them! :) Commented Jul 16, 2022 at 0:05
  • Manufacturers don't make entire fleets of vehicles both with and without options and then sell them. The baseline cars can have options added to them after manufacture , or at the dealer, or even after the sale. There's really no great hardship.
    – barbecue
    Commented Jul 17, 2022 at 4:26

If there was an option to install software in the infotainment system that would allow control of the seats, and the infotainment system provided no other means of controlling them, then installing the seat control software without licensing it would represent copyright infringement. Further, I think courts have held that copyrighted software can use time-based licensing if the nature of the license is disclosed before people pay for it.

If someone were to develop a device that could be used to isolate the seat heaters from the vehicle's main CAN bus and instead supply them with commands to control current flow, I don't think that would represent any kind of copyright violation, but the automaker would not be responsible for any harm that might occur to a person or vehicle as a result of using such a device. Going even more primitive, if someone were to cut the wires between the CAN bus interface and the heating elements, there would be no patent or copyright issues there, but there might be a greater likelihood of damage occurring if the seat incorporates temperature sensors, and the power to the heating elements would need to be reduced once the desired temperature is reached. If the amount of power required to heat a vacant seat to a comfortable temperature when ambient air is -40C were instead fed to an occupied seat when the ambient air was +40C, that might heat the seat sufficiently to cause injuries that would not have occurred if the heaters were wired to the control system as designed.


U.S. patent law prohibits not only the unauthorized sale or distribution, but use of a utility patent issued and in force, including, for personal use.

In case the system and/or method at the heart of this solution is subject to a U.S. patent, the mere addition of a step not necessary for the utility to operate or, if any, new benefit is achieved by it will not bring it outside of the scope of the patent, and the inclusion of each component (software and hardware) or step would directly violate it.

Whether or not that is the case is questionable, and relies on whether or not there is a patent, or BMW is the licensee of that patent to have standing for an action.

Civilly, one may be liable. However, even if that is the case, the practical reality that an auto maker would attempt to sue on the basis of a customer's individual patent infringement without the customer's disclosure or publication of such a method for others to do the same would probably be unprecedented, and any damages would only be deemed to incur from the time notice is served on such an infringer, and the infringer omitted to cease the infringement.

  • In general. “use” is protected in the patent laws internationally. From a uk gov site on IP basics. “ A patent protects your invention and lets you take legal action against anyone who makes, uses, sells or imports your invention without your permission.” Restricting use of a patented thing or method is fundamental to patents in generally. Commented Aug 15, 2022 at 15:09
  • I’m curious where that is and how they handle method claims. A method claim protects a series of steps. Often steps taken by a user. A series of steps is not something that is made or sold but something performed. Commented Aug 17, 2022 at 15:50
  • Hungary does have very liberal allowance for personal non-commercial use and experimental uses. But -- From wipolex-res.wipo.int/edocs/lexdocs/laws/en/hu/hu105en.pdf (1) Patent protection shall afford the holder of the patent (2) On the basis of the exclusive right of exploitation, the patentee shall be entitled to prevent any person not having his consent (a) from making, using, putting on the market or offering for sale a product which is the subject matter of the invention, or stocking or importing the product for such purposes; Commented Aug 18, 2022 at 1:46
  • thanks - from the information I came across is looking this up, the country does have very liberal exceptions for non-commercial personal use and also for research use. Commented Aug 18, 2022 at 1:56
  • That says you can't patent things that are contrary to "public ordre", the French invented the idea. Might be a sex toy or gambling device or weapon. Nothing to do with use as a general thing the patentee can control. Commented Aug 18, 2022 at 2:07

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