Garmin nuvi 310D GTM12 TMC problems

perussell · Frequent Visitor Joined: May 12, 2006 Posts: 292

Fascinating and a little worrying. Based about 4 miles from M4 in Wiltshire have journeyed to London and N Wales since buying this unit last week (with the 6025 charger cable). Have hit no major congestion so cannot be sure if the TMC unit is working OK. On the other hand approaching Bristol last night my T/master Freeway unit suggested a couple of miles of congestion on the M5 which the Nuvi didn't pick up. On arriving in the area - no congestion at all!!!
Had to call by Bristol - upon leaving on M32 unit suggested no traffic data available but on M4 seemed to have downloaded everything when I queried the unit again. Then found when I arrived home that there was no data again............
What is going on?

swing · Posted: Mon Nov 13, 2006 5:28 pm Post subject:

swing · Posted: Mon Nov 13, 2006 5:32 pm Post subject:

perussell - What is going on is that not everywhere in the country can get the RDS-TMC signal sufficiently well. Every traffic event received by the unit has a finite lifetime of a few minutes - if the event is not received again, the traffic data is removed as it is assumed the traffic has gone. If you go into these areas of no signal, the original data times out and you are left with no data on display.

On the main menu page, the bottom right hand corner icon will show a Blue Diamond if you are receiving traffic data, and you can click on this to see the list of traffic events, and a map of the country with traffic on it.

What software version are you running (Settings, System, About) - you may need to update the software via the Garmin website - if the version is too old, you won't get traffic until you apply an update.

ILoveSatNav · Occasional Visitor Joined: May 05, 2006 Posts: 25

Swing,

I have a Peugeot 407. I'm not sure what stations have TMC or not - any advice?

swing · Posted: Mon Nov 13, 2006 7:14 pm Post subject:

Ah, now the 407 has an athermic windscreen, which will be blocking the radio signals, which will affect the GTM11 and 12 (unless connected directly to the car aerial). Basically, any commercial radio station other than Classic FM (ie not local or national BBC radio stations) could well be a valid TMC Station for the Garmin service.

Whereabouts in the UK do you live, and do you travel much? If you are simply in a dead signal area, it could explain your problems, ie...

The GTM12 is being affected by the windscreen
The GTM11 is only working when in a good signal area, hence it's perceived low performance.

Also, do you have the latest firmware on your 2720 - is the GTM firmware also up to date (via WebUpdater)?

perussell · Frequent Visitor Joined: May 12, 2006 Posts: 292

Swing -
Re software, I have the latest version 3.2 which I downloaded from Garmin's site a couple of days after buying the unit.
Yes, I am familiar with the blue icon on the menu page and also the incomplete TMC coverage - that's the point :
On the M32 last night my T/master Freeway picked up a signal and happily beeped that all was clear. When I then clicked the icon on the Nuvi it said no data was avaliable which puzzles me since the Freeway was receiving inputs and both are supposed to be fed from Trafficmaster. Once on the M4 I checked the Nuvi icon again and this time it listed a whole range of traffic data starting with the M6 over 100 miles away (but no maps).. By the time I got home the TMC data had disappeared again which isn't completely surprising because the Freeway had lost its' signal by then too. However how come one unit had a signal on the M32 where Trafficmaster should have 100% coverage but the Nuvi didn't?

After reading this stream this morning I checked the coverage while sat on my drive (and powered up) and found the unit was apparently picking up from about 6 or 7 different RAC receivers with signal strengths varying between 2 and 11 but when touching the icon it again said there was no data available.
????????????

hannick · Posted: Mon Nov 13, 2006 8:08 pm Post subject: Trafficmaster Freeway v TMS

I think I made the same mistake as you are making as I have had a Trafficmaster unit in the car for years and presumed my TMS would pick up the same signal. It doesn't.
The Trafficmaster Freeway gets the signal from the small transmitters on the Motorway bridges or the dark blue poles on the A roads, and the TMS gets the signal from the main Radio masts transmitting Radio 2 etc.etc.

What a shame TMS doesn't also pick up what it needs from the Trafficmaster motorway transmitters as well. It would solve a lot of problems.

I thought I would ditch my Trafficmaster Freeway after getting the TMS for my Nuvi. Now I don't think I will as that reasuring "beep" I get from it before I join a Motorway is a must.

swing · Posted: Mon Nov 13, 2006 8:49 pm Post subject:

Yes indeed - the two devices use very different tranmission systems, so can't be compared, and both have their pluses and minuses - for example, the Freeway unit will often not warn you of traffic until you arrive at the main road, by which time you might already be caught up in the traffic and have a longer detour, whereas the RDS-TMC system should give you greater warning, but only if it's working!

In terms of broadcast, Traffimaster use many commercial radio stations - basically a station that isn't a local or national BBC station, and isn't Classic FM may well be carrying the Trafficmaster signal.

Right now, Trafficmaster don't have a license to broadcast in the FM frequency band, which they would need to be able to broadcast from their local blue posts. They also don't have the technology to broadcast on the FM frequency band, and equally the posts only broadcast the information on the immediate area too.

ILoveSatNav · Occasional Visitor Joined: May 05, 2006 Posts: 25

Swing,
I live in north herts - hatfield area. Yes I know the 407 has the athermic screen and hence I went with the 11 and wired it up tro the ariel. I was told to try the 12 - waste of time - even when it was connected to the ariel!

I'm going to try a 10 to see what that will do...

swing · Posted: Mon Nov 13, 2006 11:06 pm Post subject:

That's not North Herts - somewhere like Stevenage or Hitchin is more like North Herts! (joke).

Right, the problem with Hatfield / Welwyn, is that there is no local radio mast - you're either across to Hemel Hempstead way or the other side of Enfield for a local mast. There's nothing North until Biggleswade either. Basically, it's a bit of a dead area for signal, but once you drive about 10 miles in any direction you should be able to pick up a signal.

Jokes aside, this isn't far away from me, and I drove through Hatfield / Welwyn on Friday and noticed there was no signal.

To be honest, I don't think a 10 will do anything better than the 11 - they are both basically the same unit, it's just the 10 has the passthrough function. Be interested to know where you get the 10 from - I can't find them cheap, and I'm looking for one...

ILoveSatNav · Occasional Visitor Joined: May 05, 2006 Posts: 25

Swing, I'll let you know where I got it from when it's all installed! Tempting fate and all that!
Interesting you said this is a dead spot though, I've been all the way down the A1M from South Mimms to letchwrth and just zero! both ways!

swing · Posted: Tue Nov 14, 2006 9:23 am Post subject:

Yup, South Mimms to most of the way to Letchworth is definitely a dead spot (along with many other major roads up and down the country).

Definitely interested to hear about the GTM10 once you have it setup.

mabsey · Occasional Visitor Joined: Aug 08, 2006 Posts: 43

Well,

I'm very happy. I already had a 6025 cable and never received traffic, but Garmin sent me another 6025 and guess what, traffic lock in 10 seconds from startup and page upon page of traffic updates.

Just shows that not all 6025 cables are the same, cause I plugged my old back in and no traffic at all.

Whats even more weird, is when I go in the secret setup screen with the new cable, I'm locked on to channel 187 with a signal strength of only 3 and still receive traffic!

Mabsey

etaf · Occasional Visitor Joined: Oct 30, 2006 Posts: 29

wow - thats bad news if 6025's are also iffy Sad

Nikeboy · Occasional Visitor Joined: Sep 21, 2006 Posts: 4

I've been reading through the backlog of this post as someone who is also suffering intermediate traffic receptions problems.

I have a Nuvi 360 with a GMT12 attached.

I live on the border of North Hants and Berks. My journey to work is about 15 miles north to J11 of the M4. Plugging the GMT12 in at home I get a signal almost immediately which is maintained all the way to work (with the exception of what appears to be one dead spot when I'm in a queue to get over the the motorway junction).

Recently, I've have made some frequent visits out east along the M4. At some point (I assume around J8/9) I lose the signal. I made one journey out to Middlesex and had no signal almost the entire journey (really handy as I spent 2 hours in traffic on the M25).

Now I'm really hacked off with this, surely my problem cannot be related to signal strength around that neck of the woods.

Some sterling work has been done by those posting on this forum, but what myself and assume others that will come looking could do with is a possibly a self test check list to determine whether our problems are related to...

Signal Strength
Power Supply
Mounting
Other

Quite frankly after owning a Trafficmaster system for 2+ years before this I'm disappointed with GMT12 and honestly can't trust that I'm not about to spend an un-necessary extra 3 hours in avoidable traffic.

One other thing (as I'm a bit confused by this). Are Trafficmaster and RAC live (as listed on my Garmin) the same thing?

Keep up the good work guys.

Nikeboy

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