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.
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.
> 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.
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.
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.