I have not attempted to do what you have, but have relevant experience with vehicle CAN bus hacking. I have built a CAN emulator/translator for one of my other Chryslers, to allow a late model SATNav radio to work in a non-CANBus vehicle. I used a Teensy 3.2 (Arduino from PJRC), which has an on board CAN protocol bus. Also, I use your identical OLED. It is indeed dimable, with the right code. Will be glad to help.