iPhone GPS Signal Non-Existent

[namolnad]

Hi all,

I just purchased a one-owner 2001 allroad 2.7T @115000 mi and very meticulous maintenance records. My first Audi—which I'm very excited about! I realize it comes with some typical problems which I will likely have to address but I'm having one very weird problem that I can't totally nail down. I have a Nav system, which is more or less pointless with phones as they are, so I planned on using my iPhone for all navigation. When I started to try to use my iPhone, I realized that I had zero GPS signal inside the car (if I step outside for a few moments the signal becomes perfect again...)

I have a few theories based off of what I've read around forums, but nothing definitive, so I wanted to see if anyone had any thoughts or had experienced any similar issues.

Theories:
1. I have heard that replacing the OEM antenna may solve the issue (assuming there is somehow interference with the stock Nav system and my iPhone. Seems far fetched but the Nav system never does seem to find satellites, so maybe it's not that outlandish.)
2. There is an aftermarket Xm radio installed, which I plan on removing, but perhaps that is somehow causing issues. Seems very doubtful.
3. The car may be equipped with IR protective glass, which could be blocking the signal. I have heard this is possible, but I'm first of all not sure how to tell that I have it. Next, not sure the best way I would fix that without spending quite a bit replacing all the glass.

Does anyone have thoughts? Would love to hear more theories or experiences that people have.
Thanks!

[R490]

That would be the Xm radio antenna most likely. Especially if it's a crap off brand one.

[namolnad]

It's an on brand one, but I'm definitely going to be removing it regardless. Have you had that problem? Most stuff I've read online seems to be wishy washy on whether or not it should interfere with my phone's GPS...

That would be the Xm radio antenna most likely. Especially if it's a crap off brand one.

[R490]

It's an on brand one, but I'm definitely going to be removing it regardless. Have you had that problem? Most stuff I've read online seems to be wishy washy on whether or not it should interfere with my phone's GPS...

I haven't, but that would be my first guess as to what could be going on.

[namolnad]

No luck so far, I removed the antenna for the XM, though not yet the XM unit and the antenna wiring, and it doesn't seem to have helped the GPS signal. I'm going to be pulling out the unit in the next couple days, but I doubt that will help. Thinking I may go to my local salvage yard and try to find A6 antenna and antenna base to replace my current setup, in case that might help.

[namolnad]

I seem to have solved my problem here! I was noticing some error codes/freezing in my VCDS when it was scanning the navigation system, so that further made me thing that the system was on the fritz and likely causing the interference. I decided to disconnect the NAV unit (where the CD changer system typically lives.) After a little fussing to get access to the back of the NAV unit, I unplugged all the cords, but left it in—just in case—and replaced everything. After popping into my car to check, it seems the GPS on my phone works perfectly now!