Difficult, as I am willing to bet the rear glass needs to be removed to replace the antenna.

Replacing the antenna on Gavin's car (post above) did the trick, but quite possibly not because the antenna itself was bad. The antenna, and the wire coming out of the antenna is probably one part; cannot remove the wire from the antenna. So, replacing the antenna also means replacing the wire, which means you need to unplug the antenna wire from the splitter. Simply removing the antenna wire from the splitter and plugging it back in could easily scrape off enough corrosion to restore the electrical connection again.

Remember, the current from the antenna throug the wire and into the splitter are very, very, small so even just a little corrosion between the antenna wire connector and the splitter (as on mine) is enough to break the connection.

Pulling the side panel to get to the splitter took me all of 5 minutes.

Dan

 

The rear window would not need to be removed, the GPS antenna is installed from outside, even the wire is actually at the outside!

The wire is part of the antenna and you are right that the cable needs to be detached from the splitter (or a pass-through connector on Euro cars that do not have the splitter).

I would really hope the car in question would have the minor issue at the splitter but not all dealers would be so dumb they would replace the antenna even if the issue was at the connector.

Again, easy to check with an another antenna connected to the splitter or the navi processor.

 

Interesting to know that DB. I tried, for an hour, to remove the antenna a couple of months ago but could not get it to budge at all so I then assumed the window had to come out. Also interesting to know that the antenna wire is actually mounted "outside" as well but I'm struggling to figure out how it's routed and sealed. These kind of questions and details keep me awake at night. LOL

Thanks for your help.

Dan

 

An update, and Dan hit it on the head. I pulled connectors off the splitter (didn't notice any oxidation or anything) and even pulled the antenna connector off the back of the nav drive.

Careful examination didn't really see anything, but reseated them all real good (4 in total) and presto worked 100% better now, i had full array of satellites all day, no issues in time to lock on, or dropping sats like before.

So it was a bad connection somewhere in the chain..

Thanks Dan and DB! (Im glad I didnt have to replace the exterior antenna)



JM!

 

Thanks for reporting, we have at least two cases now with a connector issue. This is good to know for those who face a similar issue, not a big deal to check these connectors compared to trying to fix the antenna (one might conclude changing the antenna fixed the issue when actually playing with the connectors may have done it.

Antenna cable connectivity issues should be shown by a "-" indicator at the Comand satellite fix status display, I cannot remember if you checked this before fixing the connection.

Thanks for Dan too, being persistent on the likelihood of cable connectivity/corrosion issues.

 

DB, i sure did, i have the Sat Status line always displayed. Prior to my removal reseating of the cables, it would show "-" for a long time, then toggle maybe to "1" or "2" then drop back to "-" again for a long time. Never locking in.

As stated, mine is 100% better now. I still get a "-" for about 1 minute in the morning (car is in garage at night), but it goes from "-" to "3 or 4" then "7" to "11" almost withing the next couple minutes, and stays locked in.

I think getting the "-" for a bit is normal. As i have noticed in the past when I was locked in to many satellites, i would drive under an long overpass it would go to a "-" while under the bridge. Then immediately lock in once i get clear view of the sky again..

I also wanted to add, i also reseated the ground connector right beside the splitter. So that was 5 adjustments i made (3 on the splitter, 1 on the back of the Nav drive and 1 ground)

But whatever it was, mine is much better now...

JM

 

I was thinking the same thing really. Since these particular antenna's are passive I still struggle with the notion that they "go bad". I suppose it's possible that years of vibration, exposure, and temp extremes might cause them to fail but I still feel it's unlikely.

Especially after seeing how the antenna wire is routed (thanks DB) which may make it possible for water/moisture to follow the wire down to the splitter. Or, could simply be nothing more than oxidation of the input of the splitter terminal. Which ever it is, it is clear that removing/cleaning/and re-seating the antenna to splitter connection clears the problem.

I also re-seated the ground connection JM. Mine looked fine upon removal but since I was in there thought it would be a good idea.

Mine has been rock solid since the operation. SOS Tele-Aid malfunction message is gone and has not returned, not even once. Have never lost SAT signal(s), not even once. I'm stoked.

Last minor Nav issue to tackle is the occasional, and thankfully rare, problem of reading the disk.

Endless thanks to DB and Konigstiger for sharing their in-depth technical knowledge and expertise on these cars. Truly the "go to guys".

Dan

 

No, it should not be normal to get the "-" displayed (unless this Comand behaves differently), it should show "0" when it does not see any satellites (but the antenna appears fine for the navi processor).

Looks to me like an obvious intermittent connection issue, followed by a delay gaining back all satellites once the connection resumes (easy to say now that you figured out the cable was the issue).

 

How do I see how many Satellites the antenna can see?

 

Look at the bottom of the Nav screen. Among other things it shows how many sat's the unit is locked onto.

Dan

 

DB, after watching mine closely for the past 2 days, i disagree. And here is why, while watching your map screen, and having the Satellite status displayed, you will have a number of satellites displayed. I normally get between 7-11 and mine is stable now.

If i drive under a long overpass, watch your Sat Satus, mine will drop from 7 then "-" while under the overpass.

Immediately when i exit the other side it will immediately go back to 7 (for example)

So if i were having connection issues, they would not be repeatable. So to me a "-" means the NAV unit is not seeing ANY satellites. I can also reproduce this when i pull into my garage. It will go to "-"

Try it and see.

JM

 

This must be device specific then. I haven't even checked if mine shows a "-" when it looses satellites completely, will have to check this.

Thanks for pointing this, would be good to know which exact devices show zero but at least it is good to know that some indicate "-". I thought your case was just an intermittent cable connection loss but now I'm sure you have checked this and it really is from loosing satellites.

 

If I were to guess, I'd say that "-" indicates no signal and "0" (which I have seen on mine) indicates a signal is present but not locked.

Dan

 

Dan, i would agree with this statement. As being under an overpass would support the theory of "-" meaning no signal.

JM

 

I wonder if covering the antenna with something that blocks its view of the sky would yield any useful information. Haven't tried that yet.

Dan

 

Well by driving under an overpass with 2-3 feet of concrete and steel above you certainly blocks the signal. And when you have your under the overpass, your sat display will go to "-"...try it..

JM

 

The info shown at the main navi screen is usually programmable. My NTG3 allows me to select one of the four (if I remember right):
- nothing
- the current street
- Geo coordinates, including altitude and number of satellites
- ETA.

 

I just arrived from a ride with my car (W221), I actually had to visit an underground parking lot to loose all satellites. My car shows "-" for altitude when it does not know it but it shows "0" for the number of satellites when it does not see any.

 

It could be entirely possible that the NAV unit in a W221 is newer or updated compared to my (DIY) install in my W211

Im curious to see if other W211s show the same behavior when it does not see any satellites..

John

 

True Jim, but I was thinking that it would be easier to just cover it in your driveway/garage instead of relying on a tunnel/parking garage. Would also make it really easy to watch the system behaviour in an easily repeatable way.

Dan

 

I hate to admit that I only realised after driving to the underground parking lot that I could equally have tested it at home in my garage. I still did not test it but covering the GPS antenna with a metal foil should be sufficient to block GPS signals. I'm not sure if the foil would need a good ground though, this is something I have to test. Or has someone tried it already?

 

So the NAV disc itself is $249....?

Sounds a bit expensive unless it is made of gold..

Do they get updated every year or every 2 years or what?
How do I check which version I have?

 

Updated once or twice a year depending on the amount of new info. (Remember the info on the disk is about a year old when the disk is burned.) There are no late breaking developements on areas other than brand new home building developements. Your old one is good for 3 or 4 years minimum.

Eject the disk from your nav unit & printed on it is the MB Part /stock number and version number (ex: 4.2).

 

Navigation processor is located in driver side cargo compartment eject disc from processor to identify version. Current disc is BQ6460243 parts.com is showing $202.40 plus shipping, Navteq catalogs same disc as U0028-0070-809 for $249. Discs are updated about once a year.

 

Thanks Gentlemen, much appreciated.