Hi all,

I have an used '08 TCH w/ Navi, and its GPS is first/only GPS I've had (whether in-car or portable).

So, I have a question about "Menu ---> Setup ---> Calibration ---> Position/Direction" (not "... ---> Tire Change").

Why does the street address #s that GPS shows don't match the actual? (eg. I'd stop in front of a house that's "123 Main Street", yet GPS shows "155 Main Street", etc.) So, I did the manual "calibration" under Setup to synch it, and now GPS shows as if the car is driving slightly off the road, especially when in "150ft"/max view. If I fix that (re-calibrate) so that the car is driving on the road, then the displayed address#s go out of wack again.

How do I "calibrate" this? Or the address# mismatch is just a nature of (any) GPS? Is there a "reset" or "default" on this "calibration" back to factory-setup (since I seem to have messed it up)?

Thanks for your info in advance,
- PiroChu

 

Between GPS accuracy (about 20 ft radius in the best of the best scenarios, albeit I got as close as 3 ft from US survey benchmarks after few minutes of getting good fix), maps accuracy and the fact that there is no way for DVD to hold exact position of each and every street number in US (just too much data, so the numbers have approximate position, BTW same goes for road's bends and turns) it is amazing the whole thing works as well as it does. I had few GPS systems besides TCH and never came across calibration and really don't remember secret options anymore, so not sure what that calibration in the menu should do. From your description it sounds like "snap to road" function or whatever it's called. Due to above errors most car GPS systems would get car position and then display it on the closest road, even if actually calculated position is not (and in many cases it is not). Only when discrepancy between calculated position and road becomes much larger than estimated error, does the map starts showing the car off road or jumps to next, adjoining and closer road. You can see that sometimes when getting off the highway on the side ramp.
As far as the secret menu goes, I think there were some warnings posted in the same thread about not playing with it too much since some functions are not really clear and they could possibly mess the whole thing up and that goes for all secret or service menus for all electronics, that's why they are "secret".

 

The calibration function you're talking about is meant to reposition the car on the map, and not to try to align house adresses. As the previous posting says, house addresses are only approximate with most (if not all) GPS systems.

To fix your calibration, just drive to a street intersection (without any traffic), and then use the calibrate feature to position your car where you think it should show up on the map. As you drive, if it still doesn'nt look right, try it again.

Incidentally, contrary to the previous poster, this menu isn't the 'secret' menu that you may hear talk of - it is the normal setup menu that you are expected to be able to play with. You'll do no serious damage by changing these settings - although you might find things annoying when you get it wrong (as you've learned).