Comment by nvme0n1p1
15 hours ago
When I bought my current car, it came with an owners manual--for free!!
I can grab any data I want from the OBD port. The hardware was cheap, the software to use it is, again, free.
I'm not excited about this brave new world where you have to pay a subscription fee to plug a cable into a device you own and interact with it, and even less excited there are people here defending the idea.
You may not be aware but there are a lot of proprietary PIDs on your OBD2 bus you can't interpret without specialized software - you can get like oil pressure and temperature, but not say, shift points or anything the manufacturer doesn't think you should see. True right to repair would mean all of the PIDs get documented and there is a marketplace where I can purchase software or documentation without having to be a certified brand X mechanic.
I’m not sticking up for car manufacturers, but at what size or capacity should you be required to document and publish these things? It requires employer time and effort and has a cost associated with it.
As a counter argument: I was just looking at a small open source utility. As I was going through the code I found cases where certain arguments could be set to magic values that cause useful, but undocumented behavior. Should the developers be forced to document these options?
I don’t think a manufacturer should be able to lock you out of reading diagnostics on your own devices, or that anyone should be prevented from reverse engineering what those values mean. But I also don’t think there should be any requirement that they are forced to do additional work. That seems just as immoral.
> I was just looking at a small open source utility. As I was going through the code I found cases where certain arguments could be set to magic values that cause useful, but undocumented behavior. Should the developers be forced to document these options?
You were able to do that because it was open source. If a car mfr was willing to do that, it would be plenty enough for me. They shouldn't be forced to do any additional work beyond the 5 seconds it takes to type `git remote add origin github.com/honda/civic`. Then the community would have everything it needs to carry things forward.
Failing that, yes, I do think everything should be documented.
5 replies →
Between reading basic diagnostics and documenting every signal and field is routine or recurring write operations that will need to happen in the field.
Resetting the oil/maintenance light, recoding key fobs, resetting the battery stats upon replacement, etc.
I want independent mechanics to be able to do that. I also want to be able to do that myself, if I’m so inclined.
4 replies →
> I don’t think a manufacturer should be able to lock you out of reading diagnostics on your own devices, or that anyone should be prevented from reverse engineering what those values mean.
But they do do that. Also what’s the difference between a lot of obfuscation and prevention and how will you enforce that without lawsuits and discovery?
Also, what is those values have the ability to do damage and cause safety issues? Like losing your own software onto a control by wire car? Then you can rent a car and install your own software surreptitiously.
the issue is not that this information is undocumented, it's that an "authorized service center" gets information that an "owner" does not. Also cars are not "small open source utilities" with undocumented arguments; do you think that an auto manufacturer has hidden, untested diagnostics that only the dealer uses?
>> don’t think there should be any requirement that they are forced to do additional work
At one time seatbelts, airbags, emission controls, etc were all viewed in this category. Now we have regulations enforcing aspects of all of these. Why would diagnostics be different?
4 replies →
>I’m not sticking up for car manufacturers, but at what size or capacity should you be required to document and publish these things? It requires employer time and effort and has a cost associated with it.
You're talking about things that by definition have to be documented and internally published in order to design and build the powertrain in the first place. You can't design a computer-controlled automatic transmission without documenting the shift points.
The cost is therefore essentially nothing, because the information already exists. Just copy paste it into a PDF and put it on your website.
> It requires employer time and effort and has a cost associated with it.
Intentionally obfuscating the data¹ also requires time effort and costs.
¹ https://news.ycombinator.com/item?id=49674097
> at what size or capacity should you be required to document and publish these things?
The reason there is an opaque number in that open source utility is precisely because of a lack of open documentation for that register definition. Independent black box analysis of the messages only got as far as "write this value to do effect X". Whomever developed that utility would have loved to spell that bitfield out, but not at the cost of more days reverse engineering.
But manufacturers aren't reverse engineering register definitions, they're working off of vendor datasheets or protocol definitions they themselves created. All of this documentation has already been produced, as it was used to develop the tractor from its various subsystems. It just needs to be published!
2 replies →
Yes and I'm just pushing back against GP who seems to think gatekeeping that access is a good thing. And it's still way better than John Deere who (according to TFA), when the tractor detects that some wires are disconnected, wants you to pay $195 to find out which ones.
I'd love to move towards a world where owners can access everything, flash the firmware in the headlamps, etc. But all I can do as an individual is vote with my wallet and avoid the 2020s computers-on-wheels.
What you want is the service manual. Owner manual should be implicit. OBD port can work for some cars, for some of the data. But other cars do have specialized gear they require to either access either reset some stuff in some of the car's computers.
Yeah the owners and service manuals are two very very different things. You won't be performing much maintenance with the owners manual besides the absolute basics, like checking your oil.
The cheap OBD2 readers lack the vast majority of data and tools you would want to use for service as well.
There are aftermarket options but most manufacturers want you to subscribe to their service tools - often charged per monthly plus an additional a fee per VIN it touches. These cost in the hundreds to thousands. It can be pretty frustrating as a shadetree mechanic.
Notably, some vehicles like the Toyota Highlander you can’t even figure out when you need to change the spark plugs, let alone what kind of spark plugs you need from the owners manual.
Theoretically, they are to be replaced at 120k miles (!!) but they won’t even tell you that in the owners manual.
Insane.
4 replies →
Sadly service manuals aren’t commonly sold anymore and you need a subscription to a website to access factory service manuals.
It’s a shame, I use to buy the service manual when I bought the car.
Reading codes is only part of it. For the last quarter century or so (some manufacturers more than others) if you replace certain components (radio, any computer module) you need to update the ECU to recognize the new component. This requires proprietary software and in many cases proprietary hardware as well. These "features" are marketed as an "anti-theft" mechanism. This renders some repairs basically impossible for the end user to perform.
The fact that they've been allowed to build systems like that is appalling.