DIY open-source SD2 diagnostic software project

Hi all,

I've been working on some open-source software that replicates parts of the SD2 system capability. It's not a finished product, and at the moment, it's probably only of interest to those who have an engineering/software background and are looking for a DIY project. I'd be happy to get feedback or contributions.

For the most part, the ECUs supported by SD2 use K-Line communication (0V/12V) and there are plenty of USB K-Line adapters on the market. They vary in quality, but the important thing is to find one that uses a genuine (i.e. not counterfeit) FTDI chip. One of these cables -- which are generally less than 50 USD at the time I'm writing this -- will replace the specialized serial transceiver hardware in the SD2 "Tester" tablet. Most of the in-car diagnostic ports in the F355/456/550 era use the three-pin connector that was common across FIAT/Alfa/Lancia vehicles at the time. There also exist commercial adapters that will allow mating these three-pin connectors to the 16-pin OBD2-style connector used by the USB K-Line adapter.

Many of the pre-OBD2 cars supported by SD2 use an old Bosch protocol called KWP-71. There are also some that use a KWP-71 derivative named FIAT-9141, a few that use something called Marelli 1AF, and several other oddball protocols. My goal is to provide a generic implementation of these protocols in software so that they could be used with any car/ECU that supports them. ECUs in the OBD2-era cars started to use KWP2000 and CAN bus, which of course are better documented and have support from various existing software libraries. Because of this, I have been focusing on the earlier, more obscure protocols.

Regardless of protocol, diagnostics for a particular ECU requires knowledge of the memory locations at which different parameters are stored, and the format of those parameters. I wrote a software simulator of the SD2 Tester tablet so that I could connect to it with the Win32 SD2 software, and this allowed dissecting the requests/responses for individual ECU parameters.

So here's the stack of things needed for an SD2 alternative based on open-source software:

• Physical connector / adapter (e.g. FIAT 3-pin to J1962 16-pin)
  
• Serial transceiver hardware (FTDI USB K-Line cable)
  
• Software implementation of protocols. I wrote this C++ library intended for use on Linux, and it currently supports KWP-71, FIAT-9141, and Marelli 1AF (untested): https://github.com/colinbourassa/libiceblock
• Config file definition of ECU parameters. I've just built a couple of these as an example. I chose JSON as the file format: https://github.com/colinbourassa/torinoscan/tree/master/json
• Front-end software that uses the protocol library and parameter config files to actually read and display data. This part doesn't exist yet.

For reference, I've also built a list of SD2-supported ECUs, with (incomplete) details about each module's protocol, baud rate, and bus address: https://github.com/colinbourassa/torinoscan/wiki/List-of-ECUs

To build additional JSON config files for more ECUs, it's probably easiest to run the original SD2 Windows software in VirtualBox and connect it to the SD2 Tester Simulator that I wrote: https://github.com/colinbourassa/sd2-tester-sim
This allows the user to set values at arbitrary memory locations to see the reaction of the SD2 software.

I also wrote up the details of the SD2 Tester protocol here: https://colinbourassa.github.io/car_stuff/sd2/

I hope this is useful or interesting!

--Colin

 

No, I created my own config file format. I hadn't read much information about Kwp71Diag (which seems to be related to UniDiag somehow?), but that seems to be closed-source software. My intent is to make this as open/free as possible so that diagnostics are accessible to everyone.

Edit: My "torinoscan" project (on Github) is the beginning of a front-end interface, but it doesn't yet do much. I'll continue to work on it as time allows.

 

I haven't been able to find any information about the details of the Kwp71Diag config file(s), or even a working link to download it.

 

Small update:
For readability, I changed to YAML format for the ECU definitions files. The path in the source repository changed slightly:

https://github.com/colinbourassa/torinoscan/tree/master/ecu-defs