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by bluGill23 hours ago |
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upvoteby nandomrumber22 hours ago|
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Diagnostic Trouble Codes?
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upvoteby KindOne22 hours ago|
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Yes.
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upvoteby jcgrillo17 hours ago|
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That's super cool, I'm currently struggling with scan tools for a 1999 Mercedes E300 Turbodiesel. I had one that worked OK for about a decade (Autel something or other) with a 38pin connector, but it recently bricked itself with a message like "connect via USB to Updata" which I assume means its firmware somehow erased itself. Cannot figure out how to "updata" it, doesn't seem to connect via USB, the Autel software runs under Wine but doesn't appear to recognize the device... gave up and bought an iCarsoft device which sorta kinda works. It can talk to every module except for the ECU (Bosch MSA 25.1 I believe?) however if I tell the device that my car is a different model (1995-1997 naturally aspirated) I can blindly clear ECU DTCs, which is good enough because this thing is barely more complicated than a toaster. All that is to say, this space is ripe for some open hardware/software love.
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upvoteby eschneider5 hours ago|
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Interesting...1999 is probably a bit early for that Bosch to be running one of the usual ECU update protocols like UDS. It sounds like it's in the bootloader and looking for a valid executable. So the FW updater is likely in the bootloader.

If you can open it up and find the JTAG pads, it should be simple-ish to use a JTAG reader to dump the image and then you can figure out the update protocol from that. It's unlikely to be complicated.

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upvoteby bdavbdav13 hours ago|
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Not sure about your specific car, but a lot of the “consumer friendly” options like OBDeleven, Carly, etc are fantastic. You often have to pay, but a lot of work goes into them and they often just work.
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upvoteby Maxion15 hours ago|
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> All that is to say, this space is ripe for some open hardware/software love.

There's just so many computers and what-not in modern cars that this is a very tall ask. You'd need a project on-par with HomeAssistant to get anywhere.

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upvoteby jcgrillo15 hours ago|
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Yeah, it seems like more modern technology has settled on standard protocols (maybe a naive impression--someone will shout at me if that's the case) but there's probably a very long tail of bizarre false starts if you want full coverage of models back to the early 90s when computers became more commonplace.
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upvoteby bluGill9 hours ago|
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After 2006/2007 nearly everyone did CAN. I think that is even mandatory in the US, though I have no clue how to look that up (I assume there are details and exceptions) However before then everyone did their own thing. Often with custom chips that haven't been made since 2004 (or even 1999): good luck finding one that works if it breaks. CAN is cheap and allows a lot of power while hiding most of the protocol complexity. The things before that were often not as powerful as CAN, while being in practice a lot more complex because the complexity wasn't hidden.
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upvoteby bluGill10 hours ago|
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I remember getting that era working. I concluded Mercedes was trying to be clever in making a protocol so complex nobody else could understand it (thus ensuring you had to use a dealer) - and then discovered they couldn't debug it.

each body model (nothing to do with year or style) was different so clearing dtc but nothing else is not a surprise.

i did get that working, but I last touched it in 2007 so I don't remember enough details to be helpful. good luck.

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upvoteby ErroneousBosh12 hours ago|
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You don't know anything about late-90s Lucas/SAGEM GEMS ECUs do you, or Range Rover BeCMs?

I'm currently picking apart the firmware in those because it is now impossible to get replacement ignition key fobs, and it just can't be that difficult...

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upvoteby bluGill10 hours ago|
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It was 16 years ago, and I only worked with what got to the US. I don't remember much and not those at all. I saw a few how to program key fob documents but we decided that was a dealer service and so I never implemented it. still generally just send the right 4-8 bytes and press a button on the fob in a minute. In any case it sounds like you want a different end: making a fob or bypassing them was never something I got anything on.
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upvoteby colechristensen20 hours ago|
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I spent the last week successfully reverse engineering my car / various scan tools to get the right information to diagnose a fuel pump problem (and to do so without the incredible awkwardness of many of the tools)

It's pretty amazing what Claude + Ghidra + knowledgable coaching can accomplish. It was basically just setting direction, setting up an incremental workflow with the right kind of documentation, and questioning some of its theories and assumptions from time to time.

I'd love to release a lot of it but I'm torn between releasing artifacts created with expensive software I paid for and thinking that many of those things should really be freely available to anyone (specifically the things which definte the protocol to talk to the car and mapping of what various things are reported vs what they actually mean.

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upvoteby sokoloff11 hours ago|
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> I'd love to release a lot of it but I'm torn between releasing artifacts created with expensive software I paid for and thinking that many of those things should really be freely available to anyone

Release it or not, but either way you’re almost certainly going to get paid back the same amount of money: $0.

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upvoteby tclancy20 hours ago|
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Wait, why wouldn’t you post it/ write it up?
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upvoteby bluGill9 hours ago|
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If you release it people expect you to support it an answer questions. Some of them are not even nice about it. It pays to release this only if there is a group of people who will be constructive in helping make it better, otherwise it is a thankless effort.
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upvoteby colechristensen1 hours ago|
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The difference in ethics between reverse engineering something to be able to fully use/repair it vs. reverse engineering something to clone it. Also violating a license agreement I freely accepted and exposing myself to liability for IP theft. But is the IP just gatekeeping vehicle manufacturers hiding information from owners or is the IP the creation of this tool company or is it something in between
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upvoteby markb13911 hours ago|
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I’ve recently built a disassembler and emulator using Claude to help reverse engineer a 90’s ECU based on an Intel embedded cpu. It was quite impressive to watch when Claude started to use the emulator to help understand how bits of the code worked.
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upvoteby colechristensen1 hours ago|
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The juxtaposition of Claude+Ghidra being able to take apart understand and reimplement the core features of this thing in hours while also having to babysit it "no, those encrypted packets going over the CAN bus aren't from wifi" and "please actually look at the code you just decompiled instead of guessing how they work" was pretty amusing.
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upvoteby zxexz16 hours ago|
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Sorry, what are you talking about? Just release it? Are you talking about trying to make money off it? Are you claiming you reverse engineered ecu tuning software you paid for?
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upvoteby stolsvik14 hours ago|
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You really must be new to this, huh? Expensive software that you paid for?! Claude? Yes, the question is whether you want to share knowledge that cost you literally nothing, and will bring humanity one microscopic step in a better direction - or not, feeling superior in that only you have access to that knowledge. You have a choice!
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upvoteby jcgrillo17 hours ago|
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+1 on the "plz tell me how" train!
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upvoteby seany18 hours ago|
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Just dump it in a gist. That your of knowledge should be free
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