COMAND Sat Nav Problem

[Garyhum]

I have a 2003 model CLK with COMAND.

Over the last week the navigation system has thrown a bit of a wobbly. It can't locate where it is. When I program the destination the system now can't work out its location.

I have gone into settings and manually set the location, which worked fine for a few days , but now it thinks I'm ploughing fields in Wales when I was in Newbury.

When I press the map button, without having a destination loaded, is displays '00 SAT ' in the top left, which to me suggests it isn't picking up any satellites. I can't recall whether before the fault when I pressed map it displayed current longitude and latitude coordinates.

Anyone experienced this before or have any idea if it?s a fault with the Comand unit or the aerial.?

PS ? I phoned the MB help-line on the subject, there response was comical something to do with all the satellites being over IRAQ. Strange that no one else had reported the same problem , so have I got my own personal satellite ? not that?s what makes owning Mercedes worthwhile!

 

[pascal]

Em That was a good answer :twisted: From MB I mean. Comical.

Not 100% sure, but I thought that GPS satellites were in geostationary orbit (the same as sky) but maybe I am wrong. Either way it should make no difference to your receiver for any extended lenght of time.

Now I have heard of the receiver part of COMAND just breaking. MBs solution, You give them a load of money, they give you a new Comand.

But there is a few firms that put new receivers in for you, or supply one for you to fit youself for a few hundred pounds. Bear the above in mind in case below is not the problem.

Usually when a receiver goes it goes completely. The fact that it is intermitatent, may suggest (as you say) the aeriel, aeriel conection, or some other connection.

BTW: If your car is still under full warranty, make sure you make the complaint in person or by signed mail

Regarding your satellite being detained in IRAQ, I could not possibly comment, in the interest of National Security.

 

[calum]

Not 100% sure, but I thought that GPS satellites were in geostationary orbit

That's right; they are. Comical indeed.
I could tell you more, but then I would have to kill you.

 

[jberks]

MB's answer is comical, but personally, if thats the best the operator can come up with, they shouldn't be talking to customers. I know its funny, but its clearly a blatant fob-off and I find someone taking me for a fool offensive (especially when they are clearly dafter than me - I don't answer phones for a living and I would guess with a 2003 CLK, niether do you!) I would be lodging a formal complaint.

The only effect Iraq can have on your GPS is that the accuracy increases. The US turn up the power when they are using the GPS system, and down again when things are quiet. If they are charging round the desert in tanks, there is a good chance your sat nav will be more accurate. GPS sattelites are geo-stationary - they have to be, as knowing their exact fixed position is how your reciever calculates where it is.

Your fault sounds like ariel or reciever to me too. You have another few months warranty so sling it back quick - it can get a bit pricey if you have to pay yourself.

 

[The Editor]

Mmmmmm.... sounds to me as if your system is 'partially' grabbing some sats (but possibly not the four required for accurate navigation) and then maybe losing the fix and swapping over to the 'dead reckoning' feature which is a series of electronic gyroscopes and inertia sensors designed to keep you on track should you lose your satellite reception (like in a tunnel or in densly wooded areas etc).

Selective Availabilty (SA) was actually turned off in 2000 so most domestic users of GPS now have an accuracy of around 20 meters or so. The military activity should have little affect on whether you are ploughing a field or on a map somewhere.

In order to get accurate navigation at least four sats are required - Three for triangulation and the fourth will effectively give you a 3d fix in space and so enable the clever box of tricks to work out an altitude as well. Basically the more sats you are recieving, the greater your accuracy (most modern systems are 12 channel) and although there are 24 satellites orbiting the earth it's very unlikely you will get a fix on twelve of them !!!

Anyways, back to your problem.... I would hazard a guess and narrow it down to two possibles (although I'm usually wrong )

1) The antenna is unlikely to be faulty but the pre-amp contained within it could be. This would result in VERY decreased efficiency of the antenna and ultimately your GPS reciever losing sync. It will keep trying to re-establish a lock on the sats but without reliable sync you position will float around all over the place. If it is this at fault it will be a simple job of swapping over the antenna assembly (In fact this should be their first course of action as it will be easily unplugged and a new one swapped)

2) This would be the expensive one !!! - A new COMAND system (so get this done under warranty if it is !!)... If your antenna is ok but your COMAND head unit has lost it's marbles then MB will only swap the unit (they will be unable to narrow the fault down to the specific component as none of their technicians will have the knowledge or ability to work at this level)

3) Lastly (and it's very unlikely to be this) the DVD reader in the boot - but I would rule this as a last resort since it only get's it's instructions from the head unit and the fact that you are getting up maps 'in the vicinity' of where you are suggests that DVD is being read ok.

So in summary..... Antenna unit (which includes a small pre-amp), followed by the COMAND (ouch :sad: ) followed by DVD reader (but it won't be that !!)

Good luck.. keep us posted

Mark

P.S - I've just realised.. that's THREE possibles !!.. I never could count !!

 

[SLinKyjoe]

it seems to me that either the areil or receving unit for some reason is not picking up the signal. according to my book you can try ejecting your disk, switching everything off. locking the car, then get back in again and start the nav system, then place your disk in the system and let it load up.

the sallatities are in low earth orbit which means they orbit the earth once every 93minutes of so.

in fact if you go to one of Nasa's sites, I think the johnson space centre, you can get a live feed of all the orbiting objects around the earth..7000 of them...shoving your mouse over each one tells you its name. the geostaionary ones are in whats known as the clarke belt (named after arthur c clarke). they send your sky pictures to your house. you can see them too if you go to one of these sites.

if you are really boring, like me, you can go sit on a dark hill on a clear night and see the things whizzing about in the heavens.

 

[calum]

the sallatities are in low earth orbit which means they orbit the earth once every 93minutes of so.

Amazing; I was utterly convinced they were stationary, but no. Mind you, Garmin, who ought to know, say they orbit the erath twice per day, not every 90 minutes...

http://www.garmin.com/aboutGPS/

and some pretty pictures here:

http://documents.wolfram.com/applications/astronomer/Notebooks/GPSSatellites.html

 

[Garyhum]

Thank you all for the feedback. The car is still under warranty and is going in to MB Tamworth on Tuesday (28th) for diagnostics. I know the dealer is nervous at swaping the whole Comand, as apparently if it isn't faulty MB will not allow them to claim for it under warranty

I have tried different CD's (the CLK I has the Comand with a front loading CD and not a DVD). It read the map data fine as I have an older map disc that I've tried.

So I guess that does narrow it down to the Antenna or the Comand unit. I'll post an update as soon as we have a fix

I'd be keen to understand if any of you guys have Comand and press the map button twice do you get the top of the display showing longitude and latitide cordinates? I could of sworn it did before it started playing up , but now I'm just a little doubtful - must be my age!

 

[SLinKyjoe]

Amazing; I was utterly convinced they were stationary, but no. Mind you, Garmin, who ought to know, say they orbit the erath twice per day, not every 90 minutes...

http://www.garmin.com/aboutGPS/

and some pretty pictures here:

http://documents.wolfram.com/applications/astronomer/Notebooks/GPSSatellites.html

boring but there are 3 orbits for sattelites.. low, medium and high earth. the Moon is in the latter. the clarke belt is about 56,000k from earth and it is here that you find the geostationary ones....and low earth is from 150miles up. all GPS sattelitles run about in here sending time signals back to earth. you GPS reciever is loaded with all the information of these things and also ones that are yet to go up. using some good mathematics, if it gets enough info, as stated above from 3 or more, it can establish your position. The DVD Nav system in COMAND can work for around 30mins without this info before it confuses itself so if you go and get stuck in a tunnel it wont lose its place on the earth.

can anyone spel satteltile? sallatite.....oh dear.

 

[Garyhum]

Well Folks

When MB Tamworth had the car last week they ran a the diagnostic check and concluded it was my Sat Nav disc that was faulty. I was told that the CD has worn out - now being around in the 80's when CD's took over vinyl I thought CD's could not degrade over time as there is no physical contact with the CD & CD-player.

This said MB wanted to charge me £160 for a replacement disc which was alos out of date 2004/2005 (without TMC). TeleAtlas have the latest 05/06 disk with TMC for this price. I refused to buy a new disc. I knew my disc wasn't faulty as I'd tried a friends disc and had the exact same problem. MB wouldn't accept this and wouldn't try another disc themselves.

Pciked the car up and still the Sat Nav didn't work. tried it this week and same problem the car looses location on a journey over 20+ miles. So I complained to MB customer services on the 0800 number and had a phone call from the MB Tamworth dealer to bring the car back in for further tests.

They ran diagnostics again and have now confirmed that the COMAND unit is loosing the Sat link and will now replace the whole unit and a warranty cost of £2500. So hopefully within the next few days the car will go back in and finally after four visits be repaired in time for my holiday!

Shame MB Tamworth put customer satisfaction to far down on their list of priorites.

 

[The Editor]

This is exactly what I'm talking about when I said these people are not qualified to work on this sort of equipment. There is no way that the DVD would have 'worn out' through use etc. That's just plain daft and shows up their ignorance of the technology. These are commercially manufactured and pressed DVD's and the worst that would happen is the polycarbonate was faulty and allowed air into the substrate which allowed the DVD surface to oxidise. If that had of happened it would have been a batch of several hundred and not just yours.

So it was item '2' on my list of probables !! It never fails to amaze me why dealers resist and wriggle so much - Yes these items are expensive, but they get reimbursed by MB and paid for their labour so what's the big deal? The big deal is that they are scared sh*tless of making a duff diagnosis and ordering a new COMAND and then being lumbered with the cost of it !

Right - rant over :twisted:

I'm glad you got your problem sorted under warranty, you wouldn't want that bill !!

Regards


M.

 

[Rory]

MB Tamworth have really not provided the level of customer service that you should be entitled to expect from MB, it's quite appalling really.

Would the latest DVD really have TMC - I thought MB hadn't implemented it yet?

 

[Garyhum]

Ironically since they performed the last diagnostics check on the 6th July it appears now to be picking up Satellites. If I press the ?Map? button twice it also now shows the Longitude & Latitude position of the car, something during it?s faulty period it wouldn?t do.

Still waiting for MB Tamworth to ring be me back to arrange an appointment to replace the COMAND unit, which should have been 7th. But even though the unit?s now working I?m still gone get the bugger?s to replace it under warranty.

Rory - The COMAND version in my CLK (sep 2003) is the CD based version. I had upgraded the original Merc 2003/04 navigation CD with a 2004/05 TeleAtlas CD (sourced from e-bay) with TMC and this works a treat on Dynamic Routing. As previously posted by other members it does tune the radio to ?Classic FM? ? so I just have a relaxing journey listening to Classic FM or listen to a CD. ? but yes TMC does work regardless of whether Mercedes support it or not.

Earlier this week I had a lass on from MB customer service in Milton Keynes ? asking me to rate the quality of service for this COMAND problem ? needless to say I let rip!

 

[SLinKyjoe]

i was told, Friday, that Merc UK wish to improve the customer service......about time, altho it should never have gone west in the first place.....

 

[calum]

Would the latest DVD really have TMC - I thought MB hadn't implemented it yet?

that's right; we're still waiting for TMC on the DVD-based COMANDS - hopefully sometime around September is the rumour.

 

[Rory]

that's right; we're still waiting for TMC on the DVD-based COMANDS - hopefully sometime around September is the rumour.

I hope that turns out to be correct - I've still got V2.0 disk (with the dodgy roundabout exit numbers) so I'm hoping I'll get it upgraded FOC :lol: