# Navigation System Wrong Location Showing



## wsscott (Feb 5, 2004)

My Nav system was working okay (the Treg is only 2 weeks old), and yesterday it kept showing me in the wrong location. The sky was heavily clouded and we were having heavy rain. Does the weather affect the system's ability to function properly? Any ideas-Do you need to calibrate it or is there a way to reset it? Thanks


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## anothercar (Dec 20, 2002)

*Re: Navigation System Wrong Location Showing (wsscott)*

Yes, the nav requires a good shot of the geo-synchronis sats. in order to give you a good position. I have an aftermarket unit, and can see how many satellites it is picking up, I'm not sure if the OEM does. Sometimes, in very bad weather I will have a similar problem, but it grabs the satellite back in just a few hundred feet. I have a few dishes up at my office, and when the snow is very heavy I run into the same problem.


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## ZeZe (Aug 16, 2003)

*Re: Navigation System Wrong Location Showing (Leweyb)*


_Quote, originally posted by *Leweyb* »_I have an aftermarket unit, and can see how many satellites it is picking up, I'm not sure if the OEM does.

Pressing the button next to the compass icon (third button down on the right) will bring you to the 'Navigation Display.' This screen shows *GPS Status* including the number of satellites received as-well-as other vehicle position data.
I found myself in the middle of the Atlantic Ocean twice yesterday if the nav screen were to be believed...quite a shock since I thought I was in northwestern Vermont. I ejected the nav cd and reinserted it to reset the nav and the proper display came up. It was snowing here when this happened.


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## mdjak (Aug 13, 2003)

*Re: Navigation System Wrong Location Showing (ZeZe)*

That may be one reason Audi, among others, have gone with that external antenna on the rear roof of the car, probably picks up and maintains signal better than our internal one. In my opinion, though, I'd rather have the internal one. Theirs is ugly.


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## WaitingforaT-REG (Jun 29, 2003)

*Re: Navigation System Wrong Location Showing (mdjak)*

I have never had a problem, rain, snow or sun.
Drove through a driving hail and rainstorm yesterday, and had no problems whatsoever!


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## wsscott (Feb 5, 2004)

I solved the problem. I just had Crutchfield install my Alpine XM radio, and I have discovered that when the XM unit is turned on the Navigation System can't find the satellites it needs to navigate. It doesn't matter which FM channel you tune the XM radio to connect with the car's radio system for broadcast. I guess when the XM is receiving a satellite signal, this conflicts with the Navigation system's GPS system trying to find the satellites it needs. Since Crutchfield in here in C'ville I'm going to talk to them and see if they have any ideas. If anyone has a solution please let me know. Thanks.


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## jsewell (Jul 1, 2003)

*Re: Navigation System Wrong Location Showing (Leweyb)*


_Quote, originally posted by *Leweyb* »_Yes, the nav requires a good shot of the geo-synchronis sats....

Not to pick nits, but they're not geosynchronous. That's a common misconception that you see repeated often in the press, web sites, supposed "science" resources, etc. 
-J


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## wsscott (Feb 5, 2004)

Well I found an answer but not a solution. I called XM Radio, and they researched it and said that they have found that the problem exists with any combination of XM Radio units and GPS systems, including OnStar. So you can only have one of the systems function at the same time. They don't know the reason for it, and are expecting a solution to be figured out given the large number of new cars with XM and navigation systems installed. Any tekkies out there who have an explanation for the conflict, even if not a solution, I'd be interested in hearing it.


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## Uriah (Nov 2, 2003)

*Re: (wsscott)*


_Quote, originally posted by *wsscott* »_Well I found an answer but not a solution. I called XM Radio, and they researched it and said that they have found that the problem exists with any combination of XM Radio units and GPS systems, including OnStar. So you can only have one of the systems function at the same time. They don't know the reason for it, and are expecting a solution to be figured out given the large number of new cars with XM and navigation systems installed. Any tekkies out there who have an explanation for the conflict, even if not a solution, I'd be interested in hearing it.

This doesnt make sense. The GPS antenna's used for NAV arent bidirectional like the ones DirecTV uses, as far as I know.
Besides, arent you using a seperate antenna for the XM?
Uri


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## spockcat (Jun 5, 2003)

*Re: (wsscott)*

Sounds to me like the installer may have plugged the FM modulator into the GPS antenna if such thing is possible. Do you know which antenna plug he used? Here is the back of the radio:








Note the multiple antenna connections at the bottom left. You should have gone through the AUX.


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## wsscott (Feb 5, 2004)

There is a separate antenna for the XM radio. As to which antenna connection was used, I don't know. Which one is the radio antenna? When you say I should have gone through the AUX what do you mean?


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## spockcat (Jun 5, 2003)

*Re: (wsscott)*

Don't know offhand which connection is for the AM/FM antenna. When I say AUX, I mean one of the two auxiliary audio inputs. Follow the link in my signature for details.


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## jim.bresee (Nov 25, 2003)

*Re: Navigation System Wrong Location Showing (ZeZe)*


_Quote, originally posted by *ZeZe* »_
I found myself in the middle of the Atlantic Ocean twice yesterday if the nav screen were to be believed...quite a shock since I thought I was in northwestern Vermont. I ejected the nav cd and reinserted it to reset the nav and the proper display came up. It was snowing here when this happened.

That's funny - I live in Vermont, and when I was at the mall, it showed me in the middle of the Atlantic Ocean!
I had it on my list when I had it serviced - the answer was "working according to VW specification"... pretty funny!


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## rwgunther (Oct 20, 2003)

*Re: (wsscott)*


_Quote, originally posted by *wsscott* »_I called XM Radio, and they researched it and said that they have found that the problem exists with any combination of XM Radio units and GPS systems, including OnStar. So you can only have one of the systems function at the same time.

This sounds like an excuse to me. The Acura TL and Infiniti G35 (two other cars I considered) have navigation and XM radio--which can function simultaneously.


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## spockcat (Jun 5, 2003)

*Re: (rwgunther)*


_Quote, originally posted by *rwgunther* »_This sounds like an excuse to me. The Acura TL and Infiniti G35 (two other cars I considered) have navigation and XM radio--which can function simultaneously.

Yeah, but yours was probably installed correctly.


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## WaitingforaT-REG (Jun 29, 2003)

*Re: (spockcat)*

I was looking at ax XM setup at a local custom stereo shop today, and asked the Owner about the issue of antenna interference.
He said it is not possible! He said he has installed many XM setups in vehicles with Nav systems, and they all work fine!


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## wsscott (Feb 5, 2004)

The install of the Alpine XM unit I've got is pretty simple because I installed it in my Ford Explorer before I got the Treg and then uninstalled in when I had it installed in the Treg. The XM antenna mounts on the roof, its wires connects to a separate receiver box, which then connects directly to a modulator/amplifier and tuner. It has one cable that you plug the car's radio antenna into, and that cable then plugs into the radio antenna input in the radio. You then go into the radio and select an FM band, say 87.5 for ex., that's not used in your area, and select the same band in the setup on the XM modulator. That's it. To use the XM, you tune the FM radio to your preselected station, and then use the XM tuner to select the XM station. Although the input for the GPS antenna on the Treg's dash unit appear physically the same as its radio antenna connection, I don't see how you could get any function from the XM if it were connected to the wrong antenna since you then couldn't tune in a station. I may be wrong, but I don't think its an install problem or an excuse. If these other vehicles actually do work together (has anyone actually tried it or just assume they work) then since the OnStar has the same problem, there must be something in the design of these 2 systems that's a problem. Maybe in the other systems, the XM unit doesn't connect to the car's speakers through the radio's antenna-ie. maybe its a direct connection to the speakers with separate amplification for the XM. That way the 2 systems are totally independent and only share the speakers, rather than running through the head unit's electronics.


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## spockcat (Jun 5, 2003)

*Re: (wsscott)*

Sorry, I still think that the installer connected your XM's FM modulator through the GPS antenna rather than using the FM antenna. 
Do you really understand what I mean by this? Below is an FM modulator for an XM radio. Note on the left side of the photo there are two wires coming out. One is labeled "TO FM ANTENNA", the other "TO FM RADIO". If instead of using the FM antenna's connection and they used the GPS antenna's connection, then when the XM is turned on you would lose GPS signal.








Why don't you go back to the installer, ask them to pull the radio and try the other antenna plug. Then drive the car outside and see if you get satellites while the XM is on. 
While you are there, ask your installer if your XM radio has a regular audio output. Here is another photo of the XM Commander's control box. Note the two RCA jacks on it labeled "AUDIO OUT L & R". 








These can be connected to the back of the navigation radio using this connector:








Details of this are in the first link in my signature.


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## wsscott (Feb 5, 2004)

I'll check out the connections with the installer just to be sure. The Alpine unit XMA-T200RF doesn't have any outputs for speakers, only an aux input for say a CD changer, VCR, games etc. The only output from the Modulator box goes into the head unit's antenna receptacle. I'll keep you posted.


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## wsscott (Feb 5, 2004)

I met with the head of installation at Crutchfield today and we went over the installation, and there's only one way to connect the Alpine unit. He said they had been told about the conflict between the satellite signals. I gave him the article posted in this forum on wiring the Nav. system and he's going to see if by wiring the XM through the AUX connections if that will solve the problem. I also have noticed that there's some distortion in the XM radio reception. He said that the head unit in the Treg has really strong reception and it appears to be trying to bring in some weaker FM stations. He thinks that running it through the AUX would probably solve that issue too, but doesn't know if my Alpine model can be wired that way since it only has an output to connect to the Treg's antenna and thus modulate the signal into the head unit for output through the car's stereo system. It doesn't have any RCA or phone plug type of output jacks. I did discover a way however that will permit the Navigation system to track the car's location. If you turn the Nav system on and find your location before turning on the XM, it will track location properly. It doesn't show any satellites fixed (it normally shows 3), but I thought I read something that there were some kind of sensors in the wheels that tracked your location. I'll update when I get some more info.


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## spockcat (Jun 5, 2003)

*Re: (wsscott)*

So toss the Alpine because it is screwing up your nav and get the XM commander the I picture above. Obviously it has the proper output for the Touareg nav radio. I can see it in the picture.


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## anothercar (Dec 20, 2002)

*Re: Navigation System Wrong Location Showing (jsewell)*


_Quote, originally posted by *jsewell* »_
Not to pick nits, but they're not geosynchronous. That's a common misconception that you see repeated often in the press, web sites, supposed "science" resources, etc. 
-J

(PRWEB) September 25 2003--Direct-Track is the first to offer publicly, GPS|Internet tracking solutions for all cars, motorcycles, and recreational vehicles. Deregulation by the FCC of telecommunications services has made GPS/cellular technology available to the public that can deliver an affordable tracking product that can be acquired with light disposable income. 
The Direct-Track Mobile Locating Unit (MLU) uses existing cellular airwaves and takes advantage of the global positioning system currently used by the government to track cars, motorcycles and recreational vehicles. Direct-Track utilizes a constellation of 24 geo-synchronous satellites providing precise navigation and position information to the GPS receiver. 
Are they wrong? I thought they were geo-synch.


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## spockcat (Jun 5, 2003)

*Re: (wsscott)*

Some more info for you: in the below picture, the round blue plug on the right side above the big black connector is the GPS antenna. The white plug (connection 1) lower left is antenna input signal, FM from antenna module. The tan/yellow plug (connection 2) next to it is antenna output signal FM to antenna module (diversity, antenna selection).
The antenna signal input from connection 1 is checked in the radio and the result sent via connection 2 to the antenna module. If the antenna signal is too weak, the module then switches to another antenna (diversity). This process is not audible to the customer.


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## aircooled (Jul 30, 2003)

*Re: Navigation System Wrong Location Showing (Leweyb)*


_Quote »_(PRWEB) September 25 2003--Direct-Track is the first to offer publicly . . .
Direct-Track utilizes a constellation of 24 geo-synchronous satellites providing precise navigation and position information to the GPS receiver.
Are they wrong? I thought they were geo-synch.

They are wrong.
Each satellite orbits the earth twice in just under 24 hours at an altitude of about 11,000 nautical miles. In contrast, geo synchronous orbit is at an altitude of 19,323 nautical miles or 22,241 statute miles. It is fuel intensive (read:EXPENSIVE) to get a satellite parked in a geosynchronous orbit.
http://en.wikipedia.org/wiki/GPS - GPS Info
http://en.wikipedia.org/wiki/Geosynchronous_orbit - Geosynchronous orbit info

_Modified by aircooled at 12:42 PM 2-10-2004_


_Modified by aircooled at 12:44 PM 2-10-2004_


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## anothercar (Dec 20, 2002)

*Re: Navigation System Wrong Location Showing (aircooled)*

That makes sense, I can't wait to pull this one at MIT with my nerdy buddies, I bet I can win a round.....


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