CAN/Trace: Control Radio & Steering Wheel Buttons

Hello everyone,

Does anyone know of a CAN message (in kbps) that affects the radio in any vehicle type, specifically related to ignition, lights, or steering wheel controls?

I have an Android radio with a vehicle type setting in a test environment, and currently I'm getting no response.

I could also play back a CAN trace if someone has recorded how they press the steering wheel buttons and the radio reacted to it.

If something happens to me, I might be able to use filters to extract the messages.

Can I trace the CAN bus on a W169 A-Class myself using OBD? Does data simply appear through the CAN pins, or is it necessary to use complex OBD procedures to obtain any information?

OBD initially stands for "On Board Diagnostics" and doesn't directly have anything to do with the CAN bus itself. The CAN bus is just one way for the on-board diagnostics system to communicate, similar to LIN or K-line.

What you need is a CAN interface that allows you to analyze the CAN bus and potentially also send data. For example, if you want to simulate steering wheel buttons in a W169, you would also need to send the corresponding signals to the head unit's CAN bus. This cannot be done via OBD in a Mercedes because the OBD port is connected to the diagnostic CAN bus.

If you can play back a CAN trace, couldn't you simply record a new one?