Please help me to understand the GTM Status info

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Hi,

This is my last line of attack before I take a hammer to my GTM 10; at 10pm tonight the thing is history unless I can get traffic messages by then.

I've discounted the charger; now running using a USB cable from the computer

I've discounted the signal - get a strong signal in the car and through the window of the office.

I'm looking at the GTM Status screen. I don't understand many of the values, and I'm still not clear after alot of googling on exactly what the Location Table is. But the values I'm seeing are:

CC - 12 (Country Code - this is correct, I think).
SID 128 (Service Id)
LTN 0 (Location Table Number)

Now, I believe that these values should be 7 (Traffic Master) for LTN and something different (7?) for SID. But how do I make the values go correct?

I have tried clearing the FM Table as suggested in other posts - nothing seems to change here.

I'm getting a high level for most channels as it cycles through.

(btw: my FM Tables as I write this are

Frequency 1056 1017 1017 1077
Validation Code 11 11 11 11
CC 12 12 12 12
LTD 7 10 10 10
SID 7 10 10 10)

If anyone can give me a pointer, even if to tell me I'm barking up the wrong tree, that would be great.

Ta,
Rich.

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Sorry to reply to my own post, but with only two hours to go and no reprieve in sight... Smile

I wonder if I've been barking up the wrong tree in assuming that I'm getting a strong signal? Becuase i've seen high numbers under "level" in the car, i've assumed all is well.

But now i've got the unit in the office, I've realised I only see a value under "level" when the unit is in mode 3, some kind of scanning mode. When in mode 2, no signal on any channel, which I now realise is the same behaviour I had in the car.

I've now got it locked under test mode on channel 181 (Galaxy 105.6), and I'm seeing no signal at all, so I wonder if this was the problem all along - no reception on Galaxy 105.6.

Too many variables to consider I think.

mikealder · Posted: Sun Apr 22, 2007 7:05 pm Post subject:

As always with RDS-TMC problems it helps to know exactly where you are located, just the town name or city is a help, then we can check for correct frequency for the area etc.

Also it might help to know the actual GPS device and the version on software/ firmware loaded to it and the RDS unit - Mike

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Sorry about that; as I started with a vague question about LTN only I assumed the model, location etc was irrelevant. As always by waffling about other stuff I've opened the question up a bit!

I'm in Sheffield, sitting almost directly atop of the Tapton Hill Transmitter. GTM10, firmware 4.1. Nuvi 310.

Everything worked for one day before packing up.

mikealder · Posted: Sun Apr 22, 2007 7:44 pm Post subject:

Contact Garmin and arrange for it to be returned under waranty, if you are close to the transmitter it should work (unless the Tx is off line for maintenance) - does it work in other parts of the country? - Mike

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Thanks for the help Mike, I haven't travelled far enough to test it in another area yet.

For the first time in a week I'm now receiving messages using the tip on another thread of holding a station in "test" mode and preventing it from cycling.

Channel 202 (107.7 Real FM on the Tapton Transimitter) is currently delivering messages (nothing showing up on the traffic page though). I didn't think Real FM were part of the trafficmaster setup?

Channel 142 (Classic FM also has the same result - I'm not suprised that this channel doesn't result in traffic info).

So a minor move forward, but still no data.

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

And now locked to channel 181, Galaxy FM which I think is the correct trafficmaster station.

Getting messages (a little slowly), but no traffic data.

I know I've seen this kind of behaviour widely reported, but I don't recall seeing a fix for it.

Still don't understand why the LTN and SID are reported as 0 and 128 and not 7, 7.

swing · Posted: Mon Apr 23, 2007 10:02 am Post subject:

12, 128, 0 means it is locking onto Classic FM, and for some reason, not giving it up, although your FM table was listing TM stations (these may not be the local ones for your current location though). This could be for a number of reasons...

1. There is no TMC signal from anyone else to find (this could be caused by your location, or by the transmitter being broken and not transmitting any data at the moment)

2. The GTM10 isn't getting a signal (could the aerial cable have come loose?)

3. The GTM10 is actually broken

4. The weather

5. There's a "y" in the name of the day ;) Seriously, TMC is a bit of a black art, and I know places where despite near line of sight with the local transmitter, TMC may work one day, but not the next, or only if the traffic is bad on that stretch of road...

My records (thanks Mike) say Tapton is channel 181, although it's a really weak signal, so you literally might have to be on top of the transmitter before it may work (based on my experience of a similar fill-in weak transmitter, which was actually working the morning, for a change!).

I would suggest two things:

1. Drive to another area and see if it works elsewhere - this will help diagnose whether it's the local transmitter, or the GTM10 at fault. This may involve a fairly long drive, but may be more fruitful than losing the unit to Garmin for a few weeks, only for them to return is as "no fault found".

2. Try again in a day or so - it's possible the TMC signal was unavailable due to maintenance over the weekend (although Winter Hill is still offline a long time after it first stopped transmitting, so you may have a long wait).

What firmware did the GTM have before 4.10? Have you ever plugged any other GTM unit into the Nuvi (like a GTM12)?
_________________
Please don't be offended if I do not reply to a PM - please ask questions via the forums.

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Thanks Swing, useful suggestions. I have to go to Manchester for a week today so I'll try another area. I'll give the thing a brief repreive!

I'm fairly sure the nuvi is ebay bound now (and the GTM bin bound - I couldn't sell something that is unreliable - Garmin might like to consider this radical approach), but if by any chance i do start getting traffic on the Manchester journey I might reconsider.

Thanks again!

philpugh · Posted: Mon Apr 23, 2007 12:00 pm Post subject:

RichK

In the centre of Manchester it should work. My nuvi 660 picks up traffic messages (102.0Mhz from Galaxy FM) which are transmitted from the centre of Manchester. Picks them up for about 10 miles outside the city centre.

Us up here in the north-west are still waiting for TMC signals from Winter Hill to be resumed.
_________________
Phil

swing · Posted: Mon Apr 23, 2007 12:13 pm Post subject:

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Hi swing,

Yep I'm serious - will give it a week to see if anything happens - I'll be in touch then.

Same hehavior here as in Sheffield - I can force it to stay on the galaxy signal and messages pour in with a reasonable level (more than 10 usually).

But no traffic data.

One last try - am I clearing the FM table properly? Either via the diagnostics screen, or when booting up the system holding the bottom left and going into diagnostics via that route?

I feel sure this is a firmware issue as I'm getting messgaes but it is refusing to use them.

swing · Posted: Tue Apr 24, 2007 9:14 am Post subject:

Personally, I haven't cleared my FM table for a fair few firmwares now (it caused a problem a few firmwares back if you upgraded to a specific firmware - all now resolved, but I leave well alone nowadays) - one advantage of leaving it alone is that if you have visited an area before it seems faster at reconnecting by using the FM table, and not needing to search the whole range.

I'm wondering if a reset of the Nuvi may help - if the diagnostic shows the messages are flowing, then it may be the Nuvi end of the chain.

Finally, is the GTM10 a Garmin GTM10 or a Kenwood GTM10 (would have shipped in a plainer white box)?
_________________
Please don't be offended if I do not reply to a PM - please ask questions via the forums.

RichK · Occasional Visitor Joined: Nov 10, 2004 Posts: 25

Good point about the nuvi end - how do I do a reset? I've done the "start in diagnostic mode" and then resetting there - is that a full cold reset?

I did use the button at the back once, but I've left it alone since.

It is a kenwood, hope that doesn't cause any problems. I have purchased a subscription and added it, but it won't activate until I get traffic.

swing · Posted: Tue Apr 24, 2007 2:56 pm Post subject:

Yes, that sounds like the reset procedure.

Ah, now if it's a Kenwood, I do wonder whether it is a subscription problem - it certainly sounds a bit like the unit is working, but the Nuvi thinks the subscription has expired, hence why it is not giving you any traffic messages.

I wonder if the reset has removed the subscription information.

If not, I would speak to Garmin and ask them, as with the diagnostic showing it's receiving messages, it would appear to be a Nuvi problem, and not a GTM10 problem.
_________________
Please don't be offended if I do not reply to a PM - please ask questions via the forums.

	PocketGPS
	Web