If your cousin's friend changes the code for the ABS to "work better on gravel roads" and then you wreck, who's going to get sued? Not your cousin's friend - he's living in a van down by the river. The automaker is, because they're the ones with the money.
Is the litigation risk any different with software rather than hardware?
It's hard for me to pick a side here. I want that freedom, but the auto makers have a compelling reason for wanting to stop it (getting sued, warranty issues, etc). I'm 60/40 on the automaker's side.
If you really want to play with engine management, there's always megasquirt.info and wb02.com, which are more hackable anyway.
Some OEMs opt for the low settings where tuning gets detected and logged while still allowing you to run new or modified code while others only allow the flashing of signed code.
Also, as far as i know from motronic mods, they mostly only change calibration data and not the code itself, but i may be wrong.
To be specific: car makers should not be liable for unsafe modifications made by third parties, even if they intentionally made the car easy to modify and did foresee that some people would make unsafe modifications. To subject the car maker to liability in the case of a modified car, the plaintiff should have to show by a preponderance of evidence that the modification did not cause the crash.
I can see this going the opposite way too. E.g. the automaker says that they are not liable because the customer modified the audio system, even though it was the ABS that failed.
I don't buy your argument.
For example, to plug in a laptop and do a checksum of the binaries would take seconds. To disassemble an engine to find a spec'd up cam would take hours.
This would only test that the software was a known set of instructions, it wouldn't help debug the flow of the code and the run-time state:
Software and the state and sequence of events are much harder to look at and conclusively say "yes, this was the culprit".
Disassembling an engine would seem to be on the same order of complexity as disassembling and reverse engineering firmware without source code (perhaps more so).
Opening that interface or code turns that black box of deniability into potential evidence of shitty practices leading to failure in what should be safe, correct and easily tested modules.
Think global variables, 4k line functions, goto/jumps, completely ignoring industry standard practices like MISRA, etc.
It's horrifying.
A note about embedded programming on a microcontroller: global variables and goto can be used effectively and safely. Their presence or absence does not alone indicate code quality. Even a 4kloc function might be reasonable if the compiler couldn't be relied upon to inline functions into a time critical global update loop.
To answer my own question: because there are fewer court cases about home mods of automotive software, then there are about home mods of automotive mechanical systems. I think it's the lack of precedent that scares corporate lawyers when it comes to this stuff.
Maybe that should still be in Johnny's right to do, and it's up to the service center to detect what happened, but I can see why the automakers would really rather he couldn't do that.
wrong call in my books, but don't be surprised if it happens everyplace.
Some guy comes in with half a cornfield stuck to the undercarriage of their vehicle, who should pay for the suspension work? I deeply feel we should each be responsible for our own stupidity. If it is submitted as warranty, it becomes a cost to the manufacturer and I feel that is inherently dishonest. Additionally, increased costs _do_ get passed onto customers.
I get _why_ it happens, but it shouldn't.
The whole justice system is broken if we have to take the stupidity of ridiculous cases in account to tame down technological progress.
As is stated elsewhere, it's easier to determine that a physical part failed, and that it was not automaker-issued than to do the same with (e.g.) modified firmware. It's not like people are above attempting to hide the fact that they modified the firmware in order to win a lawsuit.