If you're on your originally installed disk, a new, current disk may not work properly, or crash your COMAND unit and your unit may require an audio system software update in order to work properly. If the dealer updates the system's operating software, you will get some more menu options and the bottom of the map screen will show the time of your arrival at your destination instead of your latitude/longitude and number of satellites being read. The ETA is more usefull to me.

I'd expect a problem updating to a new map disk if you do it yourself, so if you do, you'll probably need the software update.

 

Roger on that.

Is software updates part of a regular dealer "Service" or do they charge extra?

Not sure I really need an updated NAV disk as 99% of roads are the same as 5 years ago when my car was new, but being a gadget freak it always feels good to be up to date and current.

 

Relevant to updating navigation database disc, processor software update is covered under warranty, normally at cost out of warranty however if new disc is purchased from dealer update should be cost free if needed to work properly.

COMAND headunit update adding ETA, etc. again covered under warranty, at cost out of warranty. Simple process allows DIY update whether or not you update navigation database disc PM email address if interested in doing so.

 

Well after a brief period of acceptable performance, sadly i must admit my NAV is now completely inoperative. Im showing a "-" most of the time, i havent got "locked on" in 3 days, my NAV is showing im out somewhere in the Atlantic.

I even changed out my splitter with a new one. So its down to the Antenna or the NAV unit...I need someway to verify which it is...

John

 

Check your email.

 

Anyone still having problems with this? I have found the solution!

My Symptom: only 4-5 satellites normally, and after going in tunnels or after about 4 hours on the road, the NAV would lose satellite reception completely and not usually regain it, until the car sat overnight. Car was 3 years old when this started happening - everything in the back (rear SAM/processor area) looked new & shiny. On another note....anyone ever have the headlight flickering issue? That will come into play later.

What I did: 3 different NAV processors, two different splitters, 2 tries at replacing GPS antenna (anyone ever try that on the wagon - entire headliner & ABCD pillar trims must come off...). I had about enough and tore out the back of the car again.

I saw some electronic-type corrosion which had built up (did not exist when the problem started) around the bracket areas of the NAV processor. I tried jumpering a ground from the NAV processor to the chassis ground FWD of the SAM...no luck. I then took out the entire rear trim of the car - both sides, the tub around the spare, etc. Bare floor and electrics now showing. When I looked at the battery....I noticed there was a control unit inline with the battery ground - i.e. M/B does not ground the battery directly to the chassis - there is a control unit in-between. The control unit is plastic, except for the chassis bolt connection point, which is a thin metal sleeve. This sleeve routes the single bolt through to the chassis and thus the main contact of the (-) side to the chassis is where the end of the sleeve contacts a very thin portion of material welded to the inside of the rear bumper. I immediately noticed that the sleeve contact area was small, did not appear to have a great connection (slight corrosion), and I was shocked to see how thin the metal strip was that the sleeve is designed to contact!

I had two aftermarket connections (Video system) connected on the battery side - I moved them to the chassis side of the (-) battery module. Unsure if this really matters.

I cleaned the sleeve/plate connection and routed an 3x 8GA ground from this point over to a)the chassis ground point forward of the rear SAM, b)the chassis ground point aft of the rear SAM, and c) the chassis ground forward of the sub. I cleaned the NAV processor brackets and routed another ground from the SAM ground directly to the NAV bracket.

10+ satellites, immediately, after starting the car. Also no headlight flickering! Probably added 10 HP also.... This was several months ago and several long trips (with 45 minute tunnels) with no issues.

Anyway, check your grounds. Way too many electric items in the rear of this car, and IMO, a bad main battery ground to boot.

Hope this helps someone,

Smash