Houston...we've got a problem

[innov8v]

Got my windows tinted a few days ago, including the windshield with a very light Huper Optik. I mentioned to my installer that several on this board had warned about possible interference problems, given that, according to my recollection, the GPS antenna is somewhere in the dashboard/windshield area. Since I was a little fuzzy on the details, he suggested we check with Toyota about where exactly the antenna is located. After several minutes of being shuffled from one person to the next, he finally reached someone at Toyota Technical Support (that may not have been the exact title, but it was something like that) who claimed to know the location of the antenna. According to this person, it's embedded in the rear window. Hearing that, and assuming it was accurate, the installer felt we could be confident in going ahead, even though the light Huper Optik has more metal than most ceramic films (including the darker shades of Huper). Tried the NAV system for the first time today, and it's way, way off. I mean like many miles. I assume I can have the tint removed from the windshield and the NAV system will return to normal (it definitely worked prior to the tinting), but it's a painful lesson. And one that will end up having cost me quite a few wasted dollars. Word to the wise: better to trust your fellow Prius Chat members than a bunch of so-called professionals who don't know what the blank they're talking about.

[RadMarv]

innov8v,

I wouldn't jump too soon at ripping the tint off your windshield just yet. The symptom you describe is somewhat strange. I see another member here posted that HuperOptik didn't affect his NAV. Heres a copy of that post.

<div class='quotetop'>QUOTE(silly\";p=\"99442)</div>

I have my front windshield tinted too with the Huper Optik Ceramic.  If your car has navigation you do not want to use a metalic film.  My installer tried to use VCool on my front windshield but it totally cut the GPS signal.  We tested each tint by just draping the windshield on the outside with the tint film.  You can put your navigation in a diagnostic mode and see the satellites received and signals.  There was no loss of signal by draping the Huper Optik Ceramic over the windshield.  If you don't have navigation then you wouldn't have to worry.[/b]

I suggest you give the NAV another check, to see if it's just not a quirk.

[leeskarha]

I’m not an expert on GPS but I believe it evolves a time stamp from the satellites and the length of time the signal takes to reach the receiver.

http://www.garmin.com/aboutGPS/
See Sources of GPS signal errors

If the tinting slowed down the signal it would show this type of inaccuracy. Maybe you could remove the tint above the antenna only?
-Lee

[efusco]

Turn the NAV on and then go drive around for a while and see if it doesn't pick up more accurately. I think it highly unlikely the tint would affect it much if any.

[leeskarha]

This is from Cruchfield:
GPS Antenna
The navigation computer determines its position by communicating with the Global Positioning Satellite through its GPS antenna. The waterproof antenna may be mounted inside or outside of the vehicle, but best results are usually obtained by mounting it outside on the roof.

If you opt for interior mounting, keep in mind that the GPS antenna cannot "see" through metal. Do not place the antenna on the rear deck if:
you have a wired rear defroster
you have any metallic window tint anywhere in the vehicle
you have a solar reflective windshield
you have a windshield mounted radio antenna

http://www.crutchfieldadvisor.com/ISEO-rgb...on_install.html



Garmin sells this.

GARMIN Remote BOOSTER Antenna (active)
'active' antenna takes power from GPS and increases reception by 25-30% essential for professional mapping and recording reliable tracklogs
necessary for cars with metallized window tint
includes magnetic mount (holds great at freeway speeds!)
includes windshield suction-cup mount
has 8 foot cable

I'm not sure there is a way to fix this to the Toyota model but it might be an option.

[DanMan32]

According to the repair manual, and those that have first handedly observed and/or worked with the navigation system, the antenna is under the dash top, behind the display. Toyota tech should be directed to the part of the repair manual dealing with the NAV. Specifically, they should look at page 67-3. (we can't trust Toyota headquarters now? No wonder the dealers are messed up)

If you want to check the satelite signals received, go into the diagnostic screen.

[innov8v]

Thanks for the quick feedback. You guys rock! That's the good news. Bad news is that GPS still can't follow me, even after I re-calibrate my location. Have tried for the last two days--no luck. I'm off with the family for a little r&r for a few days, then I'll start to dig further when I get back. Before I start maniacally ripping out the windshield tint (I know it's Huper, RadMarv, but Huper 78--which is what I've got on my windshield--has more metal than normal, which from what I've heard can be problematic for GPS), anybody have any theories as to what else besides the film could be causing a GPS problem? Thanks all. Happy 4th.

[efusco]

Oh man, somehow I missed the "including the windshield" part of your post. I'm sure that's the culprit here. Rip and tear brother. Did you check the diagnostic screen to see how many, if any, satellites you're detecting?

[Erick]

Is it possible that they didn't really install the Huper Optic tint and instead, installed a cheaper metallic tint? When I got one of my previous cars tinted, I paid for the extra expensive tint and they pulled it right out of the same box that they used on my buddies cheaper tint job. My buddy, of course, waited to tell me this until several days later...

[RadMarv]

[quote]but Huper 78--which is what I\'ve got on my windshield--has more metal than normal,</span>

innov8v,

You better confirm that Huper 78, as I\'ve never heard of it! I can\'t even find it on Huper\'s USA or international website.

Huper Optiks website only lists Ceramic\'s in even numbers 30, 40, 50, and 60.

Huper Optik makes 4 series of films and not many within each category.

Select Series
* Select Sech (VLT=59%)
* Select Drei (VLT=35%)

Ceramic Series
* Ceramic 30
* Ceramic 40
* Ceramic 50
* Ceramic 60

Traditional Series
* Traditional 20
* Traditional 30
* Traditional 40

Security Series
* Security 008

Under their Automotive Series they list only the Select Series and Ceramic Series. Only thing close to a 78% would be Ceramic 60 but that is listed with 58% VLT.

Let us know what you got on there. I doubt it being Huper Optik at all.

I just wonder if you wound up with V-KOOL 75 on the front it\'s about the only tint that I know of with 77% VLT.

[u][b]<span style=\'color:red\'>EDIT ADDITION:

I did find out that UVSHIELD window film made by CPFilms under the Llumar brand has an exact 78% VLT rating. I wonder if that is what you got?