opendbc VS CANdevStudio

To help you get started, https://github.com/commaai/opendbc have a few Nissan vehicles with defined CAN bus IDs and the scale/offset.

Here is a good starting point for you...there are 3 Kia DBCs here: https://github.com/commaai/opendbc

The trick is finding that message... this DBC file may help: https://github.com/commaai/opendbc/blob/master/mazda_3_2019.dbc

As for the packet encoding, there's some open source info here: https://github.com/commaai/opendbc Another place to look is the RaceCapture Pro user community, as they map out CAN broadcasts for various cars and share it.

This is a really handy list of unofficial dbc files - there are a few Hyundai Kia ones in there so should be a good start. https://github.com/commaai/opendbc

There is a growing database of CAN messages for different vehicles here: https://github.com/commaai/opendbc

Luckily for me there is a lot of data to build on top - there is https://mdac.com.au/2021/04/11/dsg-control-with-rabbit-ecu/ article, there is https://github.com/RabbitECUProject/RabbitECUTeensyMCUXpresso/blob/main/source/Client/DIAG.c source code of how RabbitECU solved the same problem, and there is a https://github.com/commaai/opendbc/blob/master/vw_golf_mk4.dbc

What vehicle is that? Did you decode CAN packets or found information on the internet? Do you have any new CAN DBC knowledge to contribute say into https://github.com/commaai/opendbc which seems to be the largest catalog of DBC files?

Linux, vcan (and the can-utils), savvycan. And then you need something that simulates an ecu on the vcan - search for ecu simulator can open source - plenty of projects with different focuses. CANdevStudio and busmaster are probably the most notable ones.