Thread: Using TMC in Garmin nuvi for free

Originally Posted by itzbinnice

...Another problem I’m having is resetting the FM table. I see 8 entries, I then hit “Reset”, it clears all the entries, then slowly they come back, one by one....

It can be seen being given exaggerated importance to the radio frequencies that appear in the FM Table. They only indicate the radio broadcasters in the region. The frequency, or frequencies of interest, are those that must be tuned by the receiver, which are determined by the parameters contained in the signature. Analyzing the FM Table that you posted, I noticed that most of the frequencies are Premium because it has a $ symbol in front, and do not match their signatures. Only 106.1 7/0 (Navteq) and 106.7 4/0 (TTN) should be of interest and only one of these frequencies must be tuned, probably the strongest local signal, which can be checked in GTM Status page. On this page you can also choose to set one of the two frequencies using the Mark option (or Test in some models). When one is properly tuned Traffic symbol should appear in the navigation map.

Regarding your questions:

- "I'm hoping if I generate new key using 1527,0,0,0 it will remove those subscriptions, WILL THAT WORK?" Yes, the generated signatures will be removed with the same parameters, but always with the 0 of removal in the end

- "No new ones, just the ones I had cleared. It seems they are stuck in the GTM20’s memory. HOW CAN I FIX THAT?"
As I said, these frequencies are only indicative of the frequencies in the region. Will interest only those relating directly to signing, as in the example given above

- "I am able to update the Nuvi 765T firmware, BUT WHERE DO I GET THE GTM20 FIRMWARE? "
The firmware of the GTM20 is updated by WebUpdate, along with the GPS update. In specific cases of problems with the GTM there are ways to update it individually, but it is not the case

- "If a GTM’s subscriptions are properly recognized, can you connect it to another GPS that has a compatible connector, or must it remain with the one that generated the keys. Perhaps the Nuvi’s firmware is taking information from the GTM20’s firmware and changing things."
The GTM20 with embedded signatures will work on any Garmin GPS that is compatible with this receiver.

- "On several occasions I had entered key codes from my desk rather than have the GTM20 plugged in the car. By connecting the AC charger it enabled the Traffic feature (GTM20 attached) and I was able enter codes just as if it was connected to car. CAN THIS METHOD OF ENTERING CODES CAUSE PROBLEMS?"
The "method" does not cause any problems, it is important that the GTMxx is energized and is recognized by the GPS.

- "You state “Try unmark the Navteq from the insert page / signatures “, this is not possible since the Nuvi 765T with USA/Canada does not have that option to select different carriers."
You can manually choose a provider, setting the frequency in the GTM Status. Press Reset in FM Table and press Norm (normalize) to scan again and then set the frequency by pressing Mark in the GTM Status.