My Nav GPS is Lost

[docukost]

After replacing the battery, I noticed that my Nav system was placing my location about 100 miles to the west and tracking the wrong map location. I successsfully updated my E38 MKII Nav OS using the instuctions found in this forum thinking that that would fix the problem. However, the reported location is still wrong. I checked it against my handheld Garmin and the coordinates are in fact significantly in error. The GPS seems to be tracking OK when I drive, just on the wrong map/roads. So I think the antenna must be working OK. I entered my current location, but it still would not correct. Can you suggest a resolution to my problem?

[Brian-bmw]

How long has it been doing this since you replaced the battery?

When the nav loses power, it loses all of the tracking information it had about the satellite locations. It downlads a satellite "almanac" to help it acquire faster, and it loses the almanac with power loss. It can take 20 to 30 minutes, depending on how clear the view of the sky is, for it to reacquire the satellites and download the almanac.

As an aside, it uses wheel speed sensors, a compass, and an internal gyroscope to continue dead reakoning navigation when it can not see satellites. That is why it appears to be tracking OK.

There is a navigation service menu you can look to see what is going on. Select the "SET" menu from the main menu, and then immediately click and hold hte "MENU" button for about 10 to 12 seconds. The navigation service menu will pop up. Report back what you see under the GPS SENSOR CHECK and GPS sub menus.

[docukost]

Thanks, Brian.

I followed your instructions, it looks like I am in trouble! Here is what was reported:

Sensor Check:
Wheel Sensor: 0
GPS Status: GPS Malfunction
GPS Satellites: 00

GPS Version:
Receiver SW Vers. 0.0
Receiver SW Date: 99.99.99

Actually, the battery was replaced two months ago, and I had not used the Nav since then until three days ago. I think the car had to be "jumped" to get it started when the battery died in 15 degrees F. weather. Have I fried the computer? Can the GPS SW be reloaded?

Thanks.

[Brian-bmw]

Odds are the Trimble Module is dead. The GPS receiver (Trimble Module) is attached to the back side of a brass-colored bracket to the left of your CD changer and amp in the rear compartment. I would verify that all of its connections are sound. If it visually checks out, you will probably need a replacement. I do not know of another way to verify that it is in good working order.

Or, you could treat this as an opportunity to upgrade to a newer MKIII or MKIV nav computer.

[docukost]

Well, the mystery has been solved. As you suggested, I checked the connections. Never having accessed the panel before, I was shocked to learn that two cables, a white connecter, and a large black connector were all DISCONNECTED!

I have often suspecteed auto repair shop sabotage, but now I am even more suspicious. The battery was replaced by Holtz BMW in Rochester. Is there any reason they would have disconnected all of those connectors when replacing the battery? In all honesty if I hadn't found this BMW forum and a knowledgeable person, Brian, I would have taken my BMW back to Holtz to have the Navigation System "repaired". I can't help but wonder if they disabled the NAV on purpose. Am I wrong to be suspicious?

Anyway, much appreciation for responding to my questions.

[Brian-bmw]

I can not think of a good reason why anyone would have been in the electronics that compartment while replacing a battery. I would chalk this one up to good fortune... and investigate other BMW shops in the area.

Seriously though, I would go right back and talk to the shop manager about what you found. I would try to read the manager's reaction and see how seriously he takes it. If the manager does not seem to accept it as a plausable possibility that one of his technicians did a little extra work, then I would go elsewhere.

[arturocorso]

Hello Brian. My GPS is having the same tracking problems. My settings check shows GPS receiver error. I looked in the trunk for a brass bracket to the left of my CD changer, but didn't see anything. I have a 2004 330Cic with MKIV and v29.1 upgrade. Is there some kind of panel to remove to find the trimble module? Any thoughts? All help appreciated. Thanks.

Arturo Corso
[email protected]

[trapdoor]

Originally Posted by arturocorso

Hello Brian. My GPS is having the same tracking problems. My settings check shows GPS receiver error. I looked in the trunk for a brass bracket to the left of my CD changer, but didn't see anything. I have a 2004 330Cic with MKIV and v29.1 upgrade. Is there some kind of panel to remove to find the trimble module? Any thoughts? All help appreciated. Thanks.

Arturo Corso
[email protected]

The Mk4 Nav Computer has the GPS Module integral to the unit. I believe the GPS board is discreet and CAN be replaced, but have never seen one advertised.

Have you checked your GPS antenna is plugged in? It COULD be a faulty antenna, and I'd recommend you trying your Mk4 in another vehicle which you know is working to verify the antenna...

I believe antenna faults are quite common and replacement is much cheaper than a new Mk4

[DouglasABaker]

Originally Posted by arturocorso

Hello Brian. My GPS is having the same tracking problems. My settings check shows GPS receiver error. I looked in the trunk for a brass bracket to the left of my CD changer, but didn't see anything. I have a 2004 330Cic with MKIV and v29.1 upgrade. Is there some kind of panel to remove to find the trimble module? Any thoughts? All help appreciated. Thanks.

Arturo Corso
[email protected]

Or pop over to Radio Shack and get yourself a cheap GPS antenna. Plug it in in place of the stock antenna and leave it on your rear deck for a bit.

If the problem goes away you need a new antenna - otherwise you need a new MK4.

d-

[blk133]

Wow, yesterday I took my car to a dealer to fix the same exact problem!
I got MKIV with 29.1 update in my 04 X5. Worked fine for 3 month (after update to 29.1) and on Feb 24th, 2008 my Nav got lost, placed me 10-15 miles away from where I was. Went into a service menu and looked at GPS Status which was showing: "Receiver Error" I had no green dots anymore in the right upper corner where the sattelites should be. Almanac: No Visual Sattelites: 8

I think there is a bug in that update and we are going to see more posts with this issue. Something is wrong with BMW's NAV.

BTW here is my original post: http://www.xoutpost.com/x5-e53-forum/...receiver+error

Let me know if your problem fixes itself arturocorso.