Joes

Recently the battery in our 2009 LS460 died. After installing a new battery my wife (her car) started the car and noticed that the emergency brake was set, but she selected a dealer service option on the dash display and the brake problem was solved. Almost. When she backed it up a couple of feet and pressed on the brake pedal, there was a metallic sound like the disk pads were loose in the calipers. Since this concerned my wife and since it was time for the 55K service, we took it to our local Lexus Dealer. Two days later, we got a call to tell us that the tires were worn to 3/32 tread, so we let them replace the tires. Oh yeah, my wife also had the car detailed at the dealership.

When we got the car back, the navigation system didn't know where the car was. After reading the owners manual, we discovered that there is a navigation system procedure to update tire changes... the dealer had not done it. We also discovered a navigation system procedure to update battery changes... At the time I installed the new battery, I hadn't done it, so a couple of days late I did it.

The car still doesn't know where it is... most of the time. Some of the time though... it apparently does... for about 30 minutes or 15 miles at a time. The GPS icon randomly appears and disappears.

Any ideas? The latest from the dealer is that we may need a map data upgrade for $300, but I think it's a bad antenna connection.

Nospinzone

Hey Joes, welcome to Club Lexus!

I'm not sure what the cause of your problem is, but I can say with a great deal of certainty that a $300 Nav upgrade is not the fix.

Hang tight, I'm sure there are some members here who can provide some real help.

nsaldanh

Most likely a bad antenna connection. I don't see how a map update will fix this issue.

Valley101

Changing tires requires nothing to be done to or with the navigation if you use the same rims with the TPMS installed. I took the tires off of my car 2010 Lexus and 2012 Lexus and changed them out to preferred tires of my choice, and that was it.

jmcraney

Since all this navigation problem started with the installation of a "new battery" I would remove the battery from the car, have it tested and fully charged by a battery dealer and reinstall it. These cars seem to be sensitive to initialization with less-than-fully-charged batteries. Some "new batteries" are defective and some are not fully charged.

A system update will not improve the accuracy.

Calibration for tire size, even minor variations in diameter, and compass accuracy are owner operations. These calibrations only affect the accumulated position accuracy when the system is operating in the Dead Reckoning mode - DR is the process of calculating the current position, without the GPS input, based on the last known GPS position using distance traveled and heading.

The GPS icon is a direct indication that the system is receiving the GPS signal. Since it is not steadily on that may be an indication of a problem. You would expect that to happen when the car's antenna is shadowed by surrounding structures or terrain. Wait until you check the battery and reinitialize the car before you address that issue.

wchain

There is a notification that you must leave the car alone for 6 minutes before disconnecting the negative terminal because the nav HDD writes data.

Take it back.

Joes

Thanks to all for helping. We left the car with the dealer with instructions to drive and park it for a couple of days before calling us to say, "It's fixed." The new battery is a fully charged Optima Red Top (13 plus volts at the time of install), so I don't believe it is a part of the problem although it's installation process and procedure might well be. We should hear from the dealer by Monday... I'll pass along what we find.

Thanks again to you all.

Joes

Got the car back Friday. Fixed. No charge. No explanation. Said it just started working. Of course, I never talked to a tech person... just the service writer... who's a typical middleman.

460ing

Have the same problem, only my GPS icon is never appearing again.

Help.

How to find out if its an antenna problem?
Do I have to pull the navigation out or can I find out what the problem is?
Then what?

I have been trying to fix this for months.

Dealer wants to charge me for a whole navigation unit although its working perfectly fine. It just doesnt know where I am. After doing a lot of searching, I am pretty sure its on the dead reckoning mode.

CJITTY

Mine does the same..but oddly enough when I plug in my cell phone to charge it..the GPS icon stays on..I kid you not. Have no explanation for this at all but it always works. I have a hybrid so maybe my 12 volt trunk battery is getting weak, which is what provides aux power to all electronics in the car. Maybe the large 3300mah battery in my phone is supplying addl power somehow to keep tge GPS initialized. Weird weird weird!!

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jmcraney

Sounds like when you say "plug your phone in to charge it" you are leaving your charger plugged in all the time and just attaching the cable to the phone. That's what I do. Some phone chargers employ a switching power supply and poorly designed switching power supplies are notorious for spurious emissions that can interfere with the reception of radio frequency signals. Since your charger is closely collocated with your GPS antenna low level emissions that would not be problematic at a distance of 10 feet or more can interfere with the reception of the GPS signals. When you plug your phone in to this charger the loading probably changes the switching characteristics enough to allow the GPS signals to be received.

Try removing the charger from the power source and see what happens.

jmcraney

The GPS components in the LS460s are quiet reliable and unlikely to be a problem, except in cases of flooded cars and things like rodents chewing on the wires.

The GPS signals originate in space, so your antenna must have an unobstructed view of at least 4 satellites. As many as 7 may be above the horizon at any one time and I think at least 6 are always above the horizon. Any way, the point is that your system will not work in your garage or some place that shades the signals. I am not trying to insult your intelligence but some people don't understand that aspect. Your car's GPS antenna is located in the middle of you dash sort of under the review mirror. You don't have to worry much about tint on the windshield or stuff like that. Laying something across the dash like a sun shade might be a problem.

One of the things that you have to be concerned about is Radio Frequency signals interfering with the GPS signals. Lots of possibilities, such as, malfunctioning electronic devices that you have added to your car or devices that you are carrying or devices that someone has attached to your car such as a tracking device. RFI emissions from all sorts of devices might interfere with the GPS signals.

So, to start with, position your car away from possible interference sources, in an area that has an unobstructed view of the sky, with the engine turned off but the accessory power on and see what happens. Try that and tell us what happens.

CJITTY

The charger is a "smart" charger which shuts off power after phone reaches 100% charge. it is connected to the power from the armrest 12 volt port. An added piece to this is that my vaistech ivic unit has a plug n play connection to the back of the nav unit and head unit. It receives power from the existing head unit via the plug n play harness behind the console. The HDMI connection comes from the vaistech and connects to the samsung hdmi adapter which requires micro usb power from the armrest. From there..the hdmi connector is also the micro usb charging port to my phone which charges and provides the hdmi emulation. Perhaps the power draw away from the gps is enough to cause the GPS to not work unless there is a closed power loop or something once phone is plugged in

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jmcraney

I think you should try pulling the charger from the "armrest 12 volt port."

CJITTY

Interesting..seems to me that using the 12v armrest port would be less interference being at least 12 inches or more from dash vs port below radio but will give it a shot. I will also disconnect the iViC and see if the GPS remains stable..thanks as always for your wisdom

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