I was sure I read this somewhere, but looking at the information on this ECU, the document i have does not mention "CAN" at all

I know there are some derivatives of the PIC 18 setup that have a special CAN bus function, but have not seen any in the 8052 family that have this function. I should google this actually.

The main thing for me is the gear change speed from the time the button is pressed. I have this in my initial spec, so I will be measuring this electronically. as the gear change mechanism changes gear in 0.13 seconds, I am looking to only add a few more milliseconds to this, so I may use a user defined "interrupt request" in my setup so that the gear change is extra slick. Especially as it needs to assert the ignition interrupt request on the ECU before changing (UP) gear. anyway, this aside, yes although the end user wont "notice" a difference, in my project I need an impressive speed of gear change to match the spec my supervisor and I have set for it.