UR3 GPS Signal Loss - '05 DeVille DTS

[jjm01]

I'm new here, and I hope the outstanding group here can shed some light on this long, not fully resolved problem with the navigation radio (UR3) on an '05 Cadillac DeVille DTS with all the toys except night vision losing GPS signal for extended periods of time to the point where the screen shows the vehicle in the ocean, rivers, golf courses, another state... you get the idea:

And no, there is no window tint, junk on the package shelf - the rear window has a clear unobstructed view to the heavens.

Problem started when the OnStar system failed (DTC U1500) and the VIU/VCIM was replaced. After that, if the vehicle was parked for a while, upon restarting the "no GPS icon" would remain on the screen - sometimes for up to 20 minutes. Of course, the vehicle would get "lost". Worst part was, a DTC was rarely set, occasionally a B2462. Then all of a sudden, the "no GPS icon" would go out, and within a few moments, the vehicle position would be correct, and would work fine indefinitely until the vehicle was shut off for a while (i.e., more than 1 hour).

The dealer "reprogrammed and updated" the nav unit software a number of times, replaced the entire nav radio three times, replaced two GPS antennas, the coax cable assembly twice... all to no avail. I also noticed after VIU/VCIM was replaced, the phone functions of nav system “changed”. When voice dialing, a phone keypad came up on the nav screen – which didn’t come up before (screen keypad didn't do anything though), an “Incoming Call” message displayed when calls came in... weird.

Finally, I asked (begged) to have the VIU/VCIM completely disconnected (thinking a Class II bus conflict of some kind) for testing, since the problem started immediately after the VIU/VCIM was replaced. The dealer humored me. I then almost never saw the "no GPS icon , and the nav system worked nearly flawlessly. The dealer replaced the VIU/VCIM, the phone functions of the nav system returned to normal, but I still get the "no GPS icon" for a few minutes if the vehicle is shut off for a while, and the "no GPS icon" does come on for extended amounts of time during driving on occasion (at night for some reason). No codes now at all.

Vehicle is now out of warranty. I'm thinking of replacing the OnStar GPS antenna (even though the OnStar has not problems), figuring the OnStar GPS signal is somehow "conflicting" with the radio GPS signal. Dealer couldn't believe the VIU/VCIM was wreaking so much havoc on the nav radio; maybe OnStar antenna is also at fault.

I don't know what the heck else to do! Anyone ever deal with this?

Thanks so much in advance for any insight and assistance!

Joe

P.S. Are these cars really THAT bad? This thing has spent several months total at the dealer for everything from this to memory seats, mirros, throttle body, bad DVD, burned out switch lighting... it never ends! Now the A/C discharge line is leaking, and the shift interlock doesn't work - and there's no release lever either!

[CadillacSTS2003]

well 1st lemme ask this
have you had the onstar update done on your car to convert it from analog to digital?

[jjm01]

I kind of figured you'd be the one to respond to this... given your obvious expertise with these systems. By the way, job well done on adding factory nav to non factory nav equipped vehicles. How in the world you ever figured this out without blowing things up is beyond me. Also nice job on finding those hidden diag screens (for entering addresses while moving).

My '05 DTS already has dual mode analog/digital OnStar, so nothing needs to be updated. The OnStar VIN check confirms this.

By the way, the photo below gives you an idea of what I'm dealing with - I tired inserting into my first post from my own server space, but the whole post got bounced by spam filters with it. I've got PLENTY more examples like it.

Speaking of nav problems, do you experience intermittent voice command lock-ups? Every now and then, when I press the voice command key, I get the "OnStar ready" voice instead of the beep, then "goodbye". If I remove and reinsert the nav DVD, the voice command returns to normal. A number of nav radios and DVD's were also replaced by the dealer on this one. That one I gave up on.

I can see why GM is in trouble... my vehicle has probably had more $25,000 in list price parts replacement, and that doesn't include warranty labor and two months worth of rentals... still, I wouldn't want to drive anything else.

It's VERY unusual for someone your age (21) to be into Caddy's... God bless... you're certainly not the typical demographic for these vehicles, though I was the same way as a kid - even as a teen. Now I'm just twice your age, but when I bought my '05 DTS at 38, since the whole deal was done on the Internet, they couldn't believe a "young" guy like me was the one picking THAT car up.

Short of taking something from the GM Highway Emergency Kit and bashing it next time it shows me in the north Atlantic, any ideas?

Joe

[CadillacSTS2003]

hey thanks alot
yea i learned to drive on my dads 1993 ETC, my 1st car was a 1997 ETC (my sister now has it) and now i have the 2003 STS

i didnt realize 05s were dual and not needed to be upgraded

as for voice command lock ups do you mean when the unit is speaking or when i am telling the unit what to do, if you mean when im speaking to the unit, i actually havent had my VCIM reprogrammed as of yet to realize my car has nav for the voice command as this would of cost me 80 bucks at the dealer when i can have them do it for free when they have to reprogram it for my onstar update.

what the CHEAPEST solution and best in my opinion if your certain its the antenna is to either unwire your stock one and run it up to the front (probably not possible as ill bet its spooled in with many other wires to the rear) or buy the antenna i used and mount it up under the dash pad (far away from your onstar antenna to prevent interference if that is indeed the problem)

does the signal per chance get stronger or weaker when your using the onstar system?

[CadillacSTS2003]

oh
and its DEF a gps problem as even your DATE is completely wrong which is supplied to the unit via the gps signal

[jjm01]

No problem with the date and time, that's just an old pic... but it just goes to show you how long I've been dealing with this.

To clarify the voice command problem, it's when speak directions to the nav radio, like "go home" or "zoom in"... for example you press the steering wheel button getting ready to say a voice command and instead of the nav beep, you get "OnStar ready" followed by "goodbye". But it doesn't happen all the time, and when it's stuck like this, if you remove and reinsert the DVD, all is fine.

Not a biggie, the GPS signal loss and inaccuracy bothers me far more.

I'm not looking for the cheapest solution by any means, just the one to get thing working right again the way it used to. I ordered two new GPS antennas, both the same for the OnStar and UR3 radio... at least that what the parts department tells me.

By signal getting stronger or weaker when using OnStar, I suppose you mean checking it by going into the "GPS Info" diagnostic screen discoverd by Joseph0263, correct? I'll check it out. Speaking of those diagnostic screens, is there supposed to be any data in the "Gyro Vehicle Signal"? Mine is always showing zeroes.

Thanks for all your insight... old guy like me taking orders from a 21 year old, LOL!

[CadillacSTS2003]

the voice problem is simple thats your VCIM needing programed to recognize you have a nav unit...

no
you should have gyro
heres another question
when your DRIVING around does the arrow turn around at all or is it lock in at dead East

if you feel though your tests it is DEF onstar interference then the cheapest route would be to buy another GPS antenna, the shorter one which is the replacement for the nav, and install it under your front dash pad