toyota, Avalon xls, 2003 Nav system

I have a toyota avalon xls, 2003 with the nav. system.  I would like to know how to override the speed sensor so that I can operate the menu on the Nav.system.  Also I would like to know the location of the the wiring to by-pass. 

Thanks to all in advance.

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george

I have a 2003 Lexcus with the same problem! If you find a solution, I would like to know also.

Couple of things, there shouldn't be an overide for this and if you disconnect the speed sense the nav is useless. Nav systems rely on "dead reckoning", what this means is that the nav will acquire your position only on startup and then uses a speed sense, reverse light, and a gyro to tell you where you are. I could be wrong on the new navs, but I am pretty sure they are this way.

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Certified Security Specialist
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I believe the navagation system relies on a GPS sensor to tell the system where the car is.  The menu is turn off and not accessible when the car exceeds a few mph.   The speed sensor is what may be doing this.  Anyone with any ideas that may help? 

Thanks,

George

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george

It does rely on the "gps" portion of the system only at initial startup, after that it switches to dead reckoning(explained above). This is why if you go through a long tunnel, or parked in a garage, it can still tell you where you are (gps uses an antenna that needs a clear view of the sky, so if you where in your garage, or lets say you where using it to track the vehicle with something like onstar and the thieves parked the car in an underground garage, there would be no way to tell you where the car is). If it relied soley on gps then there would be no use to have a speed sense wire, or a reverse wire and gyro, on the unit because it wouldn't need them. The company that manufactured the unit deemed it necessary to build in a safety feature that doesn't allow you to access menus when driving, so unless you are good at rewriting the units programming, will probably have to live with it the way it is. You could try and hook a relay up to break contact with the speed sense wire and use the menu, but then you wouldn't be where the nav told you that you where.

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.