That is correct, the clocks are indeed coded to the original ECU and it's VIN, also, Euro-3 clocks are not compatible with Euro-4 ECU's.....So you cannot use 15/16 clocks on a 17, 18 or 19 and vice-versa. You can't just buy another set of clocks from a wrecker and plonk them in, it just won't work. Mileage and ECU info is kept in the clocks.
I "think" compatible new/second-hand clocks may be able to be coded to the bike via GS-911, otherwise it's a dealer job.
Smithy.