Install the error code eliminator from DDM ($15 for a pair), and you will not get an error code, and you won't have to have the dealer set "Xenon present." Its also best to keep the dealer uninformed of your mods in case you have a warranty claim for electrical later on.
The error code really depends on which HID kit. Its relatively cheap to add the error elimination into the circuitry, and some kits have it built in because its good for marketing, e.g., "works for all cars including Mercedes, BMW, etc."
I have the DDM kit with error code eliminator installed, and there are no problems, and no need to get "Xenon present" set.