Sat Nav Losing Lock

P

Phoenix

Member
 Leeds
Hi All,

Very occasionally my sat nav will lose lock and tell me im int eh middle of a lake... lol.

Once this happens it doesnt re-gaint he lock until ive left it overnight.

Also once it just restarted itself as if it had overheated or something.

Had it into the dealership but they just say they cant reproduce the issue.... anyone else had similar issues?

Its going in to the garage this weekend for another session to see if they can find the issue..

:headbang:
 
Mine did it yesterday for the first time in a long time, was convinced it was about 500m from where it actually was.

IIRC there's an automatic syncronisation between the car's believed position (using wheel sensors) and the GPS.

on X5World I saw a procedure to reset it, but it was basically head to an open space and take lots of left and right turns and it will sort itself out.

Do u have the latest maps? If you're on a new road that it doesn't know about that can't help.
 
Well had it in to the garage yesterday and they "upgraded the software".

So we shall see how it goes.

Ive got the 2007-2 map set. It just seems that for a £2.5k sat nav its not very good! No full postcode search and every couple of weeks it thinks im in a lake somewhere....

They say there are no fault slogged so im just assuming its "one of those things".
 
Yes i believe that it can indeed get confused with wheel sensors. When i was having a play in the snow this winter (Snow + empty private carpack + RWD car + big kid :roll: ) my Sat Nav went completely crazy on more than one occasion... It thought i was going in completely the wrong direction and didn't reset until i left the car a while.
 
mine has done this a few times, but I wondered if it was due to me having modified maps with speed camera alerts :oops:

I have found sometimes that ejecting the DVD fixed it, but last time it didn't so I just left it overnight and it was fine the next day.
 
I'm pretty sure the sat nav takes continuous readings between the abs sensors measuring actual and relative rotations, so it can calculate how far you have driven, turned, etc. Useful in tunnels, high buildings, etc. when signal may drop.

My guess though on this is more likely the DVD player is not reading the disk, be it the disk dirty or scratched or the laser. Leaving overnight just allows the system to shut down, reboot and calculate its position.

People with damaged or pirate disks often suffer with this sort of fault, or freezes.
 
The disc itself looks like new - and apparently no errors were logged by the system.

I wondered if it was because id activated the "perspective hidden mode" maybe? I mean if this mode was actually 100% working why dont BMW make it a normal option rather than being done through the hidden system menu...??

I wondered if the system may have been overheating or just doesnt work right in 3D.
 
Phoenix said:
The disc itself looks like new - and apparently no errors were logged by the system.

I wondered if it was because id activated the "perspective hidden mode" maybe? I mean if this mode was actually 100% working why dont BMW make it a normal option rather than being done through the hidden system menu...??

I wondered if the system may have been overheating or just doesnt work right in 3D.
Click to expand...

I see no reason why it would overheat when it's designed to work in any part of the globe. Hardly that hot here and there is no heat source near the DVD.

The system works perfect in 3d and has on both my BMW's for a couple of years. I've also had multiple discs on both cars and the only time I have ever had an error is whe the disc was dirty fingerprinted or when I've been messing with the OEM discs to add features and created a poor copy (of my own originals of course)

There are many reports of the laser reader not working correctly and on some boards guides to clean and or replace it. If you get to the point of being told that's the problem then you may want to investigate it as a new DVD unit is big ££'s as the dealers. If you can hear the DVD spinning constantly it maybe that the disc is not reading correctly due to one of the above 2 suggestions.

I'd start by swapping the disc with someone else with a 'no problem' BMW system for a couple of days and see what happens.
 
Hmmm I echo a lot of the above, except I don't think it's DVD related.. I think regardless of where the car relates itself to be on a map, if it's calculated the wrong position, this is the problem.

There's a way of checking the wheel sensors in the same Perspective hidden menu, and also will tell you how many satelites you're locked onto. I'd be wondering about these a little more, perhaps in case the gps aerial has an intermittant connection and the wheel sensors are confusing it.

Only thing I'd try and do is maybe park it right next to another MK4 nav unit and compare settings, maybe after a drive around the block too.
 
Its such an intermittent occurance though - as one of the other posters has said - maybe once a month at most. Will monitor the situation over the coming months to see how it goes. Ive still got 18 months warranty left anyways...

S>
 
Andy - I know where you are coming from, but my comment re the dvd was to eliminate the obvious first. If you try another disk for a while and it's perfect then you have solved the problem, if not then go for the more challenging stuff.

However, if it's just once per month then it's going to be hard to find and you maybe chasing something that is going to be a fruitless task.

If they can't replicate BMW will always sidestep doing anything.

I guess it has to get worst first
 
I had this but couldnt get it to pick up the GPS sats again to re establish the true position, even after leaving it for days ejecting disc etc etc. At the same time it did a few 'shut down restarts' of its own accord while i was driving. Took it to local dealer and they replaced the whole unit (DVD drive & aerial). Cost well over £1k (warranty obviously).
 
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