Freematics Forum

Many automotive manufacturers set the other bytes of a PID to certain values for special diagnostics.
Ex; PID 0A Fuel Pressure is only 1 byte but you might see changing values in some of the other bytes
33444 7E8 8 04 41 0A 07 90 E5 00 32

It would be very useful if the remaining bytes could also be set to values.

Thanks and the Freematics OBD-II emulator is a great and very useful product.

What does the remaining bytes indicate?

They can mean anything. Mostly will be related to the PID but providing additional info. For Fuel Pressure PID, the remaining bytes could mean the state of other Fuel System components and functions. The auto manufacturers do not publish this because it is not required by law but the info but may be used for their dealer diagnostics or system development diagnostics. We used a lot of empty bytes in PIDs to do exactly that when I was developing engine systems. I have also seen this recently on a 2014 car for most OBD-II PIDs.
I suggested it to see if there would be any interest from other Emulator users or if you thought it would be useful. Obviously implementation depends on complexity and how many users would request it.