bobsnyder

The navigation system on my 2002 SC430 usually doesn't get GPS and gets lost very often. Is this common?

tfischer

No, it's not.

intdiamond

iTrader: (2)

Welcome to CL.
A few questions:
Did your GPS ever work properly since you've owned the vehicle?
Are you in a very remote area? Sometimes the GPS gets 'lost' if it's way off the beaten path, or if you are in a newly-developed area. If it happens when you are in heavily populated areas, you may have a GPS antenna issue. Did you have your windshield replaced? The antenna runs down the center of your windshield. Do you have some kind of electronic device that sits on your dash, that may interfere w/GPS reception? If none of the above applies to your situation, you should probably go to the dealer and have them analyze your GPS system.

tfischer

The GPS should not get "lost" when you are way off the beaten path. The system does not know if you are on a road or not. I was driving through West Virginia (I think) in 2003 (or so) and I drove on a stretch of newly opened expressway that was at least 50 miles long. The road was not on the maps because my DVD was a few years old, so the screen showed me driving through what appeared to be an empty field. My location on the map was accurate, it was just that the road was not shown beneath the car.
There is GPS coverage all across North America, often by 4 or more satellites; I think you need 3 for the system to locate your position. The only place you would lose connection would be in a tunnel or a forest, or perhaps in an urban midtown.
If your system is getting lost, you have some sort of a problem. There are several diagnostic tools built into the NAV system which somebody at the dealership should be familiar with.

thang tran

Have you ever updated your DVD navigation with the copy one ? If you are new owner , check your Disc version , shoul be 0.1 for 2002 model . Most copy one have that problem

tfischer

Don't use a copy; they are unreliable.
The NAV system in the '02 models is a Generation 2 system, and, on some later cars could be a Gen 3 (although mostly they were on the '03 models); the differences are not important here, since they both take the same data disc.
The '02 cars were mostly delivered with the Version 1 software. The current Version is Ver. 8, so if you still have Ver 1, this would be a good time to update the data.
The above post is fairly unintelligible, and I don't think he is telling you to use a copy; perhaps what he is trying to get at is that if you still have a Ver. 1 DVD data disc in the car, you should be aware that putting any higher version into the drive will not only give you new data, but will also upgrade the operating system. After that, the Ver 1 disc will not work, but any version from 2 to 8 will work, and you can swap those back and forth all you want.
My SC and my RX have different Gen NAV systems, (2 and 3), but they use the same data disc. I have one Ver 6 and one Ver 8 at this time, and, for a road trip, I will swap them so the the Ver 8 data is in the car going on the trip. (The belief that these discs are never backward compatible applies only to going back to Ver. 1 after using a higher version, and I'm pretty sure about that.)
However, I would think that the upgrade to the operating system would have no effect on the problems associated with the NAV system "getting lost," although it's possible. While using version 1, and while taking some long trips with it, that never happened to me, and I am so average that you should feel free to extrapolate my data to your personal situation.
My guess is that you have an antenna problem, or some electronic or even mechanical problem with the NAV unit, and I would have the dealer take a look at it for a professional diagnosis.