Garmin Traffic Subscriptions

You'll have to call Garmin

I recall a discussion here some time ago about having both Clear Channel and Navteq subscriptions on the same device. The opinion at that time was that if you came into an area where both services were active, the device would lock onto the 1st service it saw and there was no way the user could select one or the other. This sounds like what may be happening.

If this is in fact what happens, then Garmin would be the one who might be able to disable the Navteq service permanently on your 755T.

Before making the leap, you might try relocating the power cord for the nuvi to see if that improves the Clear Channel reception as I believe the antenna is part of the cable. Since you said there were times that you couldn't get any traffic on the 755T, this might be that your cable is not in the optimal location to receive a weaker Clear Channel station.

I use the bean bag mount and recently started taking the slack out of my power cord/antenna and laying it on the dash behind the unit. The bean bag sitting on the cord keeps it from sliding back. Reception has improved TREMENDOUSLY and I now get service in fringe areas where I didn't used to receive any updates.

First before the repost,

You cannot remove a Navteq (nor any other) subscription from the GTM traffic receiver. Garmin themselves cannot even remove a traffic susbscription. Once it's applied to the unit, it's there for good.

Second, the GTM unit is auto-sensing when there are multiple subscriptions on the unit (more info later in the repost) and will choose the strongest signal when scanning and lock onto that particular subscription.

Begin repost
With the unit powered on, connected to the GTM xx receiver and receiving traffic:

1. Go to the map screen
2. Touch the "speed" display to go to the Trip Computer screen
3. Touch and hold the large round speedometer gauge for approx 6-7 seconds
4. Touch the "next" button to advance to the "GTM Info" page.

The left-hand column under "FM Table" displays the available stations/channels that are broadcasting traffic data and that are seen by the GTM xx. The list displayed is of stations/channels your unit is able to select from. Here's an example of what you'll see (will vary according to your area, traffic provider & subscription):

TTN-LAX3 103.5 6/6 $

Description of above (AFAIK):
TTN = Total Traffic Network, Navteq = Navteq
LAX3 = Region name (the numerical value will change)
103.5 = Station/channel frequency
6 = Station/channel ID (6: TTN, 7: Navteq, 12: unknown)
6 = Location
$ = Identified/verified/locked stations/channels usable by GTM xx

You can also see what station/channel is currently being used for traffic data on the previous "GTM Status" page in the right-hand column under which will look like:

Channel: 152(102.7)

This will change according to which station/channel is selected from the FM Table list on the "GTM Info" page. At bootup, the FM Table is scanned and (I believe) the most powerful station/channel is selected by the system to provide the traffic data. I also believe (but have not verified) that the system is able to switch to a different station/channel automatically when the signal goes below a certain level and/or another stronger station/channel is available in the FM Table. The FM Table is also re-scanned periodically (you'll see the FM Table being refreshed) but I'm unsure of the exact frequency.

If you have two traffic subscriptions on your GTM xx as I do (original Navteq Lifetime subscription unit with additional Clear Channel Lifetime subscription) the system will decide which subscription is used for traffic data and is NOT selectable by the user in any way that I know of. The first & strongest signal will be the deciding factor on which is used. However, if the stronger stations/channels consistently belong to one provider, the system will purge the FM Table of the weaker stations/channels. For example with my GTM 20, Clear Channel is dominant in my area...I seldom, if ever, now see any Navteq stations/channels in my FM Table where I used to see them quite frequently. And yes, both subscriptions are indeed valid, usable and seen by the system.
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Additional info: Clear Channel/TTN vs Navteq traffic (Los Angeles area)

In the Los Angeles/Riverside, CA area, I get the following stations transmitting traffic data:

Clear Channel Lifetime (Los Angeles)
92.3 94.1 98.7 99.1 102.7 103.5 104.3 105.3 (8 stations)

Clear Channel Lifetime (San Bernardino/Riverside)
92.3 94.1 98.7 99.1 99.9 102.7 103.5 104.3 105.3 (9 stations)

Navteq Lifetime ad-based (Los Angeles)
91.9 94.9 97.3 100.3 105.9 (5 stations)

Navteq Lifetime ad-based (San Bernardino/Riverside)
100.3 (1 station)

You can see that Clear Channel is the clear winner as far as transmitting stations are concerned, at least in my area and I find that it's well worth adding the Clear Channel lifetime subscription in addition to the GTM 20's Navteq subscription just for the additional and wider coverage.

If you'll be using a Navteq only GTM 20 with a 760, you may in fact need to purchase the Clear Channel lifetime subscription to add to the GTM 20 since the 760 has no means to display the ads that the Navteq subscription relies on. I am not sure of this because I am running an old firmware version (v3.20) on my 760. When I used it with my Navteq only GTM 20 (before adding a Clear Channel lifetime subscription), traffic data was very sporadic, incomplete and definitely not working correctly. After adding the Clear Channel lifetime subscription, traffic was verified working correctly. Newer firmware versions (4.xx) for the 760 may have fixed this but I really do not know. Maybe a 760 user with firmware v4.xx with access to a Navteq only GTM 20 can comment on this.

You may get wider coverage using Clear Channel but this will depend on your particular area (Clear Channel is -much- better in my area).

Clear Channel Traffic coverage map:
http://www.totaltraffic.com/CoverageAreas/

Navteq Traffic coverage map:
http://www.navteq.com/rdstraffic/

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Additional info regarding multiple subscriptions on one GTM 20 (4/8/2009)

You can purchase a Clear Channel lifetime subscription and apply it to a Navteq only GTM 20. I have done just that on the GTM 20 that came with my 765T. Two subscriptions are on the unit, Clear Channel & Navteq.

You can also purchase a Navteq only GTM 20 direct from Garmin and add a Clear Channel subscription to that. Yes, this really is a Navteq GTM 20; read the fine print and note the price compared to the Clear Channel GTM 20.

Navteq GTM 20 - $119.99 https://buy.garmin.com/shop/shop.do?pID=36249
Clear Channel GTM 20 - $214.27 https://buy.garmin.com/shop/shop.do?pID=403

You can also purchase a Navteq subscription and apply it to a Clear Channel GTM 20. That does not make much sense though unless coverage for your area is better using Navteq. The system is auto-sensing (with no option to the user as to which subscription/provider will be used) and will choose the provider with the strongest overall signal if you have multiple subscriptions.

See https://buy.garmin.com/shop/shop.do?cID=268 for available traffic subscriptions.

Hey DorkusNimrod,

Thanks for the very in-depth explanation. Your post is awesome!

I've got the lifetime sub that came with my 755T, and have thought about getting the additional Clear Channel sub. Does anybody have any experience with which one is better in the Chicgaoland area?

-Jeff

I stopped renewing my subscription, but would reconsider if these are lifetime.

Garmin has since moved to only full lifetime subscriptions with the GTM traffic receivers. They no longer offer it on a yearly basis. Now, how long "Lifetime" is good for is anyone's guess...just look at how long "Lifetime" was on the MSN Direct GDB 5x units.

I have a Nuvi 660. Recently I drove from Washington DC to Atlanta. When I got close to Atlanta there was a traffic jam on the interstate. Even though I have lifetime traffic on my unit, there was no warning on the gps. The problem was that it was still communicating with the Charlotte, NC traffic center. Once I unplugged and replugged the nuvi in, the Atlanta traffic popped up. What a drag, as I was already stuck in stopped traffic.

BTW - It was my iPhone that alerted me to the traffic ahead. At that point I re-examined my gps and figured out that it was still locked in to the Charlotte, NC station.

So, if I have the traffic receiver, can I use Clear Channel instead of NavTeq, or do I need to purchase both? Clear Channel's map looks more comprehensive.

You can use only Clear Channel, only Navteq or even both if you already have a valid subscription on the unit. The number or combinations of subscription does not matter. If you're in the reception area for which the subscription is valid, the unit should work. You can even purchase an overseas subscription, apply it to the unit and use it overseas. The subscriptions are no overwritten but added to the unit.