I have a device that will respond to PID requests on the vehicle CAN bus. i.e. I can set it to whatever PID value/format I want. e.g. PID 36 Lambda. My ECU does not have PID 36. So, it does not show up in the supported PID list ( Mode 1 : PID 0 ,32, 64, etc.)

But, if I make the PID 36 request, directly on the CAN bus, the data comes in perfectly. Lambda in ((A*256)+B ) / 32768

The stock ECU, apparently, just ignores the request. So, I can ask for it from 0x7DF or 0x7E0 and the device responds, in place of the stock ECU.

Can I use the custom PID mechanism to log data from this source ? This would make life so much easier; and eliminate the voltage offset errors, scaling/config issues, etc. by getting rid of the D/A A/D stages, entirely, and using the digital data, directly.

Thanks.