Does anyone know if the Lexus NAV disc is the same as our TCH disc?

I have what I think is the Lexus 7.1 disc. After a little playing around with it I cannot get my system to read the map content. The system loads, I just get an error reading the maps. This could be because I tried a 5.1 LOADING.KWI file as an override hack attempt.

Thanks,
Mike