VAG Blocks

VAG Blocks is open source (GPLv3) beta software for reading VAG group specific measuring blocks from an OBD-II port using an inexpensive ELM327 type adapter. Both Bluetooth and USB adapters have been tested on Windows & Linux. Sample rates of up to 12 samples per second have been achieved.

Various control modules are supported such as the engine ECU and gearbox. Values such as boost, oil temperature, DPF soot loading and current gear can be plotted in program and logged to a CSV file.

You will need a label file for each module to determine what the values mean. Without a label file VAG Blocks will only tell you the units of the parameter eg. You might see a value of 80 °C but without a label file you cannot determine if it is the oil temperature or the coolant temperature. Plain text VCDS/VAG-COM style label files and redirect files are supported by VAG Blocks.

Currently the communication protocol is unstable and the software is still in beta phase. The ELM327 is designed for reading OBD-II PIDs and its raw CAN mode is limited which makes implementing VW TP 2.0 difficult.

References KW 1281 Protocol (German)


Any donation is appreciated.


Windows binary - Version 1.0.0 beta
Released 15 January 2012

Source code


Hi Jared,

I can see you made quite a lot of work on VAG diagnostics some three years ago. Have you abandoned the project?

I have started my own diagnostics software based on ELM327, written in Java. My idea is to make it as simple as possible, just a framework, where the whole functionality including communication would be configurable in XML files - commands, response parsers, descriptions. I believe, if it is simple enough, a huge community of DYI guys would contribute doing the reverse engineering on their cars and creating and modifying the configuration files. And if designed properly, it could be used for generic OBD as well as proprietary Volkswagen protocol or others. My motivation is I have Skoda Octavia II which I need check from time to time. The commercial diagnostics is very expensive for home use.

Pls, let me know if you would be interested in such project - if you could contribute or provide some advise.



Add new comment