Force navigation sync?

That's never happened to me. If I have moved the map from where I am, I press the MAP button and that snaps it back to my location.

 

Very odd problem... luckily something i haven't had to deal with. I don't know if there is a way to force it to update your position. However, i can propose a few ideas as to why this might be happening:
1. Your actual location is correct, there's something wrong with your map CD (unlikely)
2. The nav system takes as input your speed, direction (forward/reverse), and compas direction. One of these could be off. for example, if your compas is off by a little bit, you would gradually shift off the street (although the nav would try to match you to the nearest street).

It might be easier to document the problem (for example, photographs of the nav showing you in the middle of the ocean when, infact, you are not) and take it to your dealer... that is something that should be covered under warenty as defective.

 

I haven't noticed it since the 4.2 upgrade, but there was a stretch of Route 74/76 in NC where I'd be show driving off the road by about 100 yards. The same thing happened in the mountains of PA and WV at least twice. In all cases, eventually I'd be 'correct' again.

However, 60 miles is far beyond that issue. It's like your GPS antenna is turned off, and the 'dead reckoning' that's a fallback isn't very supportive.

One of the service menus includes a list of 'visible' GPS satellites. I don't have directions handy, but if you can get them, next time you seem 'off' check to see if you have any GPS assistance...

 

You didn't say what year you have. The nav systems may differ.

Check if you see the "GPS" letters up near the upper left corner of the map view. This means the nav is properly receiving satellite signals. If they're not there, then it uses dead-reckoning to try to determine your position. (Dead reckoning uses time/distance. It counts tire revolutions.)

 

Boy I have to say you can not force a GPS to "sync" you are either getting a signal or you are not! I have waded out hip deep in the woods to get a signal to end a dispute over position. The dead recoining in the Prius uses the speed tire rotation and inertia and turning monitors to supplement the GPS. Trust me if you are driving through a forest with tall Douglas Fir on other side or the "canyons" of NY city your may not be the greatest. There dead recoining cuts in and it is a god send. Get it?

 

What region is it set for?

 

<div class='quotetop'>QUOTE(KTPhil @ Apr 4 2006, 11:57 AM) [snapback]234817[/snapback]</div>

I think KTPhil has pegged your issue. If it is set for the wrong zone, it defaults to the dead reconing mode. The easy way to tell is if the GPS icon is displayed under the compass needle. To delve a bit deeper, you can power up the veh, hold the info button down, and cycle the light on/off three times and it takes you to the Nav and Avec/Lan codes. Select nav and then I think it says GPS data.....you have 8 "slots" off satelites displayed. You will see "-", "T", or "P". - is no signal, T is a time hac only from the satalites to allow dead reconing, and a P is positive lock for GPS. You need 3 P's for accurate triangulation. You have to shut the car off to exit this mode. Also take a look at the "vehicle sensor" srteen and make sure your gyro voltage is stable, and the pulse per mile seems to increase with veh speeds. But I suspect you are in the wrong zone.
There are 2 navs and this info is for the more popular, so if nothing is as I said, ping us back.
Regards, Mike

 

Do you have something blocking the GPS antenna? The antenna is just forward of the center speaker in the dash. If you place a radar detector or something similar in that area you may be blocking antenna reception.