openxc-diag options and arguments

openxc-diag is a command-line tool for adding new recurring or one-time diagnostic message requests through a vehicle interface.

Make a single diagnostic request

This example will create a new one-time diagnostic request - it will be sent once, and any respones will be printed to the terminal via stdout. The --message-id and --mode options are required. This sends a functional broadcast request (ID 0x7df) for the mode 3 service, to store a “freeze frame”. See the Unified Diagnostics Service and On-Board Diagnostics standards for more information on valid modes.

The bus option is not required, and the VI will use whatever its configured default CAN bus if one is not specified.

$ openxc-diag --message-id 0x7df --mode 0x3


The vehicle interface must be running firmware that supports diagnostic requests.

Create a recurring diagnostic request

This example will register a new recurring diagnostic request with the vehicle interface. It will request the OBD-II engine speed parameter at 1Hz, so if you subseqeuntly run the openxc-dump command you will be able to read the responses.

$ openxc-diag --message-id 0x7df --mode 0x1 --pid 0xc --frequency 1

Command-line options

A description overview of all possible command line options can be found via --help.