PURPOSE
This project is an API to interface with the EXLAP protocol.
EXLAP BACKGROUND
EXLAP is found in many vehicles produced by the Volkswagon Auto Group (VAG). Where avaliable, EXLAP allows you access to many different vehicle telemetry sources such as brake pressure, wheel speed, seatbelt status, steering angle, and potentially controls such as those found in a vehicle stereo/entertainment system. This project was tested against EXLAP commands avaliable on specific models of Porsche vehicles. More commands likely exist in other VAG model vehicles, and are easily discovered using this project.
EXLAP was seemingly designed as a standardized method for manufactures to interface with vehicle systems over a common API. VAG attempted to evangalize adoption of this protocol, but it seems those attempts were unsuccessful and now abandoned.
Through the EXLAP documentation found from 2017, I was able to release this project under a Creative Common license.
The longevity of EXLAP is unknown, however it has been used in cars as recent as 2024, and it will remain functional in all cars previously shipped with it, so continued exploration of this protocol seems worthwhile. I could not identify the first year EXLAP was shipped, but I would guess it is around 2012 - 2015.
USE
Credentials (creds.py) must be provided to speak to EXLAP authenticated commands.
You can find credentials for your model vehicle several ways. Existing apps that interface with your vehicle have hard coded credentials, the EXLAP server running in the vehicle likely has unprotected memory or files you can read.
Full demonstration of protocol is limited without authentication. Unauthenticated it is still possible to test connectivity by issuing the Req_Dir('*') command to an EXLAP server. This will result in a response showing avaliable commands, but likely will be very limited.
Modify the main.py file with the ip address and EXLAP commands you wish to issue the server.
PROJECT INFO
This project required a patch to asyncio, and assumes python 3.10.9 is present. Likely, it will work on earlier version of python 3. XML schema was pythonified using https://www.davekuhlman.org/generateDS.html
Main files of interest:
exlap_cmds.py - contains function for exlap commands and auth
exlap_v2.py - DSgenerate of exlap xml schema into python objects
exlapv2_subs.py - flexible python function for exlap cmd
main.py - connects to exlap server and issue commands
streams.py - patch for asyncio python streams
- src/ src code
- docs/ project documentation, exlap schema files
- dep/ project dependencies such as python patches and imports
- samples/ demonstrations of basic project capabilties
Some future idea for this project are better parsing of exlap responses
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Validation of data sources and format ()
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Test access over USB (the protocol says it supports it)
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Test websockets (also documented but unable to establish a connection)
Known Issues:
EXLAP Authentication was not as documented in the schema. MD5 appears no longer used.
Websockets connection upgrade did not function as documented in schema.