In the US, car manufacturers are required to honor the warranty for the rest of the car after you swap the engine unless they can prove your engine swap caused the failure they don't want to repair. They will probably have little difficulty proving that for a scenario like a more powerful engine breaking a transmission. They'd have a much harder time claiming it caused the heated seats to stop working.

This SDK seems to be for PC-based remote control apps, not camera firmware. A well-designed camera firmware would not accept remote control commands that exceed the hardware's safety limits.

That's not the problem. The problem here is that Fuji appears to be claiming that any use of the SDK voids the warranty entirely, regardless of the defect. t would be like if you swapped out your car's engine with a more powerful one, and then, from a completely unrelated fault, its navigation system stops working.

In the US, my understanding is that this is explicitly not legal, per the Magnuson–Moss Warranty Act. FujiFilm can choose not to offer a warranty at all, but if they offer one, then it must cover defects on modified devices unless they can show that the modification caused or contributed to the defect.

In the EU, it is my understanding that it is legal to have a guarantee with terms like these. However, regardless of any guarantee the manufacturer may offer, there is a statutory guarantee in the EU for most products, which completely ignores the terms that the manufacturer might prefer. This usually ends up being weaker than Magnuson–Moss in terms of duration and modifications. But it usually means that for six months, the seller must prove that the fault with the product was caused by the consumer, and for two years, if you can show that the problem is from a defect with the device originally and not from you, then you can still get repairs, replacement, or a refund.

The short answer is: The warranty must cover damage not caused by your modification.

There are no countries i'm aware of that require you warranty damage caused by user modification. Lots of countries require that you do not void the entire warranty, or refuse service, of any damage not caused by the modification, and generally the manufacturer has to show the damage was caused by the modification if they want to refuse service.

In this case, Fuji is trying to void the entire warranty. That is not legal in a lot of countries.

A more apt analogy would be the MVD plugged a dongle into the canbus plug and now your warranty is void.

I mean, this is exactly what they are doing.

And isn't that normal? If you remap your ECU to use a different fuel mixture that voids the warranty right? That's what google results overwhelmingly say. And it makes perfect sense. Users might alter the firmware to run at a suboptimal setting that increases wear. Would you expect a manufacturer to honor warranty if you bolted on a turbocharger?

No, not right.

I'm seeing sources indicating that yes, it will void warranty. Both in the US [1] and K [2]

1. https://carperformanceboss.com/ecu-tuning-warranty-legal/

2. https://hyperchips.co.uk/will-a-car-remap-affect-my-warranty....

> If I swap out my car's engine with a more powerful one

yes, legally required to be covered in the us.

> and screw up the drivetrain will warranty cover it?

No, not legally required to be covered in the us.

The difference is the law specifies the manufacturer can not assume a leads to b, they have to a reason to think b was caused by a.