Reading this about the errors, I wonder if the cause is the 50W HID require to much start-up current?
I have the 35w with digital ballast and never had a problem.
Before installing it I did a test with a meter I have that has a memory. It peaked at around 4A draw when first starting the bulb and around 3A running.
A 50W incandescent bulb will draw 4.16A # 12V (P=IxE)
So my starting current of 4A is around what the normal bulb uses in power.
I don't know what current the can-bus uses as a threshold for over-current, but I bet the initial start-up current of the 50W HID is higher then that threshold on some of these lights 50w lights.
Believe me when I say the 35W HID emits enough light