Do Not Sell My Personal Information Jump to content

Sat Nav And Clock Adjustment Woes With 1999 Mk 4 Ls

Recommended Posts

Just can't get my Sat Nav system to work consistently or adjust the clock so that it remembers the time.

Thought I would pester you chaps one last time to see if anyone has any ideas as to what might be wrong.

Sat Nav - I can set a location (well nearly always) using road name and town etc. I can calibrate my location. I get directions to a destination fairly accurately. Problem is I have to do this all over next time I want to use it even for a return journey as the system seems to forget where it has gone which can't be right. When I turn on the map screen prior to using the system am I correct in assuming that I should see on the screen my location? Does the in car system work like my Garmin does?

I have read the little owners manual cover to cover which was not much help.

I have had a look at the cd drive in the boot to make sure that it is dry etc and all connections are OK and it seems fine. The previous owner updated the maps CD but I am not sure what version it is.

Clock Setting - this is really puzzling me, everytime I get in the car the clock is wrong, I reset it through the Sat Nav setup screens but as soon as i turn off the ignition is defaults to some daft time. I have noticed that when you reset the time there is no button to press to log what you've done. It appears that the clock is linked to the operation of the Sat Nav in some way which may explain why the two do not appear to be functioning properly.

I have scoured the net and am none the wiser. I would like to get hold of a Lexus maintenance manual but don't seem to be able to locate one for the LS - at least then I could attempt to trouble shoot before taking drastic action by disconnecting the Battery etc etc.

Any help would be most appreciated before I empty my wallet at my local Lexus dealer.

Link to comment
Share on other sites

Errr if its loosing memory does it have a permanent memory power supply like some after market stereos require. Or maybe a Battery memory back up like pc's?

Probably daft questions but throwing it out there just in case.

Link to comment
Share on other sites

Errr if its loosing memory does it have a permanent memory power supply like some after market stereos require. Or maybe a battery memory back up like pc's?

Probably daft questions but throwing it out there just in case.

Good call Pete.


Link to comment
Share on other sites

  • 2 weeks later...

Hiya. I'm not sure about the LS400, but I had a minor problem with the gps on my 2002 430. I presume it's similar.

If so, you're right in thinking there is a device under the cover under the front windscreen - its more than just an antenna, it's a complete gps unit that sends time and position details back to the unit in the boot, which then does all the processing. It does sound as though this isnt doing its job properly.

The first thing I think I'd do is to check the fusebox. There is a backup memory of the car's position, and it sounds as though it might be losing this. When you start the car, it should remember where it is, and be ready to go straight away. If it's not that, then I would suggest that you do disconnect the Battery for ten minutes. Be aware that you'll need a code for the radio to use it again. Your dealer may be able to tell you what it is, or it may be in the service history booklet, carefully concealed on the inside cover with the word RADIO next to it <g>. This is what sorted my unit out - it had become confused, and stopped working.

The route guidance does continue to work when there is no signal, or when the gps unit is not working. Wierd, I know, but what happens is that it counts the turns of the wheel, and has a compass to tell which direction the car is pointing in, and does it's best to use that. It means that in wooded valleys and tunnels and things the sat nav doesnt let you down.

The gps unit should know where it is when the car is restarted - unless you've been on a ferry or something - then it may take ten minutes or so to find satelites again. Does it manage to find itself in the end if you don't set it? And does it sometimes make mistakes at roundabouts?

The minutes of the clock are controlled by the gps. This makes your clock more accurate than the beeps on the hour from the radio, even. But you can on the 430 at least turn this off, so the clock runs by itself. Its somewhere on the menus - I can't tell you where. Sorry

Oh, also, there should be a GPS thing that comes up on the screen when it can see satellites. Does this come on at all?

Anyway, good luck with it. I do understand the person above saying about is it worth it when you can get a tomtom, but really, also, if you've got something, its nice to be able to make it work!

Link to comment
Share on other sites

Interesting to read what you mention about the GPS unit. I was flicking through the sat nav manual and saw in the info on the map screen a note about the GPS. It appears that if the GPS is working you should see a GPS icon on the map screen but I dont see this.

I have not had my car long but when I bought it I noticed on the passenger side at the top left hand corner of the windscreen a small rectangular box with what looks like a short antenna, it was hanging down so i wedged it into the screen trim to conceal it. I now wonder if this has something to do with the GPS but cant see any reference to it in the manual. The car does have a Clifford alarm fitted so I suspect this is the internal movement sensor.

I will try the Battery disconnection trick and see if that helps, as you say if the car has equipment fitted you would expect it to work so i'll persevere.

Link to comment
Share on other sites

Latest Deals

Lexus Official Store for genuine Lexus parts & accessories

Disclaimer: As the club is an eBay Partner, The club may be compensated if you make a purchase via eBay links

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


Lexus Owners Club Powered by Invision Community

eBay Disclosure: As the club is an eBay Partner, the club may earn commision if you make a purchase via the clubs eBay links.

DISCLAIMER: is an independent Lexus forum for owners of Lexus vehicles. The club is not part of Lexus UK nor affiliated with or endorsed by Lexus UK in any way. The material contained in the forums is submitted by the general public and is NOT endorsed by Lexus Owners Club, ACI LTD, Lexus UK or Toyota Motor Corporation. The official Lexus website can be found at
  • Create New...