OBD-II UART board not working with another device on the CAN bus

I have had much success running the OBD-II UART board with my microprocessor reading various things (TPS, RPM, etc.) through the OBD-II port. Just recently I tried running it with a ‘Y-splitter’ and another device. The unit seems to gets lost or stop working altogether. Wondering if there’s the possibility that the other device is conflicting with the OBD-II UART board through the communications. I wait at least 100 ms before sending another command. After removing the other device and reinitializing, the OBD-II UART board returns to working as normal.

Any ideas?

The splitter is likely acting as a voltage divider and corrupting the signal, or the timings are interfering with one another.

You might be able to wire them in-line together and space out the timings, though (instead of splitting, make a chain? This might have other issues, but could be worth a shot)

Good points to consider, but unfortunately I don’t have control of the other device.

One thing I want to try is put 2 OBD-II UART boards on the splitter and see if that works.

It’s frustrating that theoretically you should be able to have several devices connected to the CAN bus and so far nada.