Thread: Using TMC in Garmin nuvi for free

I try to answer some of your questions, but my experience has been higher with GTM25, 26 and 35. I think you should not worry too much about the limit of signatures. I've seen GTMxx with a large number of signatures of European countries that worked very well, it seems that the limit should be something more than ten signatures, at least. The removal signatures are not added to the total number of signatures, as one would expect, they reduce the total counted. The possibility of having reached the limit, the GTMxx should simply refuse to sign, it seems most likely. In this case you would have to delete some and install the new.
The frequencies that appear in the Navteq FM Table are tuned from the parameters of the signature Ltn, PID .. (in case, Navteq). When the signature is correctly recognized by the firmware of the GPS and recorded in the GTM, the name of the provider (Navteq) appears in the signature field and in the field of frequencies. If the signature field of the FM Table, the TTN provider appears correctly (incorrect appears "no name") but not corresponding to the frequency that appears in the left field (only the Navteq) is possibly an indication that the signature can be refer to another country, be incomplete or may require more than one key (may also be compatibility issue, but I can not say). In short, if you do not receive channels TTN, or key signature is incorrect, incomplete or is not compatible (update the GPS and GTM20 firmware). Another question occurred to me now: you are certain that both Navteq and TTN services operate at the same time? It seems unlikely. Try unmark the Navteq from the insert page / signatures