[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!