hms09

My nav system in my 2007 LS460 has gone haywire. Thinks I am maybe 5-10 miles away. Is there a way to reboot the system and bring it back on track? Or is this a dealer only fix? Expensive?

Thanks,
Harry

jmcraney

You can reboot the Nav System by disconnecting the car's battery for a few minutes.

I don't think that will help your situation. Sounds like you are operating in the Dead Reckoning mode.

roadfrog

Mine does this once a month or so as well. All you can do is recalibrate. Easily done. Simply go to your nav menu at the bottom of the page list and hit "calibrate". Then, touch the screen arrows to bring the crosshairs to where you are currently parked and hit "enter", then turn the arrows to orientate the direction your facing, then hit "enter": again. Should be good for a while after that. I'm not sure why mine starting doing this, but may have something to do with my window tint. Nav systems are sensitive to metallic films, and other interfernces.

hms09

I don't see the Nav menu . Is it the same as your 2008?

roadfrog

Yes it'll be the same. I'm doing this from memory cuz i'm not near my car, so bear with me....

Go to either the info screen (bottom left) or the menu screen (bottom right). Then press the settings icon and at the bottom of that list (2nd page) is the calibration setting.

roadfrog

I remember now,

Press "Menu" and the press "setup".

Then at the bottom of that screen will be the calibration. Don;t use the calibration for tire change. You want the other icon on that page that says "position direction".

hms09

Thanks, found it and recalibrated. Haven't driven it yet but will tomorrow. I'll report back

roadfrog

Awesome. Yes, please do report back!

hms09

Got it working again. I had no idea you could recalibrate the Nav system thru the Menus. It took a few times working with it but finally got it. It's amazing what you can learn on this forum! Thanks to all that replied.

Harry

roadfrog

You're welcome and thanks for reporting back

hms09

Well, it has happened again. My nav went haywire again. I was able to recalibrate but afraid if I am away from home and it happens I will be stuck. Guess I will have to take my Garmin along. Wondering what the group thinks about taking it to lexus. Are they simply going to do the same thing I have done or do they have a more sophisticated method that may be more permanent on a fix. Has anyone else experienced this on and off situation with their Nav unit?

Thanks,
Harry

jmcraney

Harry,

I am sorry you are having problems with your car's navigation system.

It is a very complex system. The owner's manual is sort of vague is some respects and some of the information is too technical for most of us to understand.

Your concern that you might not get good resolution at a dealership is very astute. Since these systems are very reliable, the dealerships don't have much opportunity to gain experience and expertise in troubleshooting them - they would likely just swap components and that can give very misleading results.

I will try to give you some basic information to help you get started.

The car's nav sys operates in two modes: GPS and Dead Reckoning. It switches between these two modes automatically. If the GPS signals are being received, it operates in GPS and if the GPS signals are not being received it operates in DR. There is a direct indication on the map display as to which mode the system is using. If you can see "GPS" in one of the blocks along the left margin of the display, then it is in the GPS mode.

There is no "calibration" for the GPS mode. In the GPS mode the car's position in space (3D) is calculated from the Time Difference Of Arrival of signals from the GPS constellation of about 24 satellites that are orbiting the Earth at an altitude of about 12,000 miles. At least 4 of these satellites can be seen from anyplace on the Earth's surface that has an unobstructed view of the sky. Accuracy is just a few feet.

The car's nav system is unlike handheld GPS devices, like cellphones and Garmins, in that it can DR navigate. It uses the car's magnetic compass and distance-measuring sensor (one of the wheels) to calculate the car's position based on direction and distance traveled from the last known position. "Calibration" allows the car's compass to be adjusted for local magnetic variation and allows for an adjustment for different sized tires. For the vast majority of us the factory default calibration will give very satisfactory results for the life of the car, but the capability to make those adjustments is there if you want to. Even if it is substantially mis-calibrated there is no impact to GPS position accuracy. The heading display may appear cantered if the compass has a substantial error but most operators don't even recognize that. In the DR mode the car's position error is the result of sensor errors and distance traveled - that means that the position error gets larger the farther you drive.

So, Harry, you need to tell us if the car is in the DR mode?

Here are some links to prior GPS discussions that might have some information that will be useful to you:

https://www.clublexus.com/forums/ls-...gnal-loss.html

https://www.clublexus.com/forums/ls-...n-problem.html

https://www.clublexus.com/forums/ls-...n-compass.html

https://www.clublexus.com/forums/ls-...formation.html

https://www.clublexus.com/forums/ls-...n-problem.html

https://www.clublexus.com/forums/ls-...s-jammers.html

https://www.clublexus.com/forums/ls-...s-2012-ls.html

https://www.clublexus.com/forums/ls-...s-compass.html

https://www.clublexus.com/forums/ls-...-of-whack.html

hms09

I do not see the "GPS" indicator so I guess it is in the DR mode. But I have been driving the car for 2 days now and so far its been spot on after I recalibrated. Just waiting for it to go out again.

hms09

It went out again so I made an appointment with my dealer. Anyone know what to expect or what to look out for before I go?

Thanks a bunch
Harry

hms09

Took my 2007LS to the Lexus dealer yesterday. They recalibrated and everything has worked fine for the last 2 days. Also had to jump start the car and needed a new battery. Could this have been the problem all along?

Also, I still don't see the "gps' on the left side so I guess I am still in DR mode. How do I get to gps mode? Could it be a bad antenna?

Thanks for all replies.