Dealer doesn't seem to be much help. CD based nav system in a 2004 C230K. Symbol for car on map is way off of actual location. I'm on the freeway, the system thinks I exited... why because it wanted me to? It lags about 300 feet behind the actual location, so it tells me to turn after I already have. It shows me on the freeway when I have exited and vice versa. Today it told me I arrived at my destination and I was 2 streets away, so with each turn it told me again. Why is the system so far off? Satellite shows 7, MBUSA says below 3 it becomes inaccurate. What are they missing. This thing is going to kill me if I actual do what it says. Help!
Oh, I've already been through the recalibrate from front to rear tires, that has neither any validity nor impact. I'm in the #1 lane of a 5 lane freeway and the system tells to to turn right in 1000 feet and I've already past that exit. Because of this, if I make short turns on small streets, it has me on the wrong streets... can't catch up. They just think I would be happier with a DVD based system, but it's too late, not an option. Thanks.

The system probably is using dead reckoning instead of satellite signals. There is an icon on the screen that should display you are getting the GPS signals. I am betting it's not there now. If memory serves it looks sort of like this: (((o))). You should have a manual for the COMAND that shows you all this. There should also be a screen I believe labeled "Service" that tells you exactly how many satellites you are receiving, probably reading "0". More than likely the problem is the GPS antenna, or maybe the splitter.
Assuming you have Teleaid, you can try a test call on Teleaid and ask them if they can see your location, that usually narrows it down. If they can see your location, I'd guess the splitter, if they can't, it's inconclusive, could still be the splitter. The antenna by far is the most common problem.
Make sure you are testing all this with clear view of the sky, and if you try a test Teleaid call, and also don't do it right away after say leaving a parking ramp or garage area, anything under a roof or covering.
The dead reckoning feature is supposed to help keep the map up to date in short distances with a blocked view of the sky, like a tunnel or parking ramp, etc while driving, eventually it goes off course due to tire slippage, etc, a small bit has a large effect over time.

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

I do not believe I have Teleaid , because I thought it was a subscriber service, but I'll check that out. The shop foreman drove with me and although I've never seen the icon for the GPS signal, when the general map of the route displays it shows I am getting signals from 7 out of the max 8. Where is the antenna located? I was on open road so there was no external blockage like a bridge or parking garage, etc, but the way it sounds is like something is preventing it from zeroing in closer than 300 or 400 feet, alreadys behind my driving. MBUSA says the "locator" needs adjustment. Shouldn't a dealer know that? The dealer says there is nothing they can do. That's how its designed. I'm not buying that or thousands of owners would be up in arms. They just replaced the nav system because the old one had a scratch on the screen. They claim they reinstalled the old one and it does the same thing.. but the old one worked, this one is driving me crazy. Thanks.

OK, you may not have Teleaid, no problem.
Yes, there is a screen you can go to where you pick out an intersection on the map, and press "confirm" or something when you are at that point. If you are getting a bunch of sat's (over 3 or 4) then it's not what I thought, I would do this position confirmation thing. Check it out in your COMAND operators book.
Anyways, yeah you go to the street list and pick out something close or that you'll be passing over. In my case I used to use for example "W Beltline Hwy" and "Fish Hatchery Rd". I'd exit off the Beltline Hwy onto Fish Hatchery Rd where I would get turned around to go back to the dealership. Right when I was exactly over this highway overpass I would push the "accept" or "acknowledge" or whatever the button said, that confirmed I was AT that intersection. I'm sure they have regular city street locations too that you can pick out. Should cover this in the manual. This is a rough outline of what they're telling you about, the manual should explain the procedure better, and NO idea why they can't do this for you!!

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

There are supposed to be 2 ways to calibrate. One on intersection, the other by tires. I've tried them both. I live at a T intersection. The destination flag is dead on. So I set that as a destination as well as a separate one for my actual address. Either way when it calibrates the route and takes me home, the flag is in the right place, but the "blue" route you follow is a block farther away. Do you know where the antenna is? I just read a lengthy dissertation on another forum and you both make a lot of sense and obviously the dealer should figure this out, but they aren't. In the meantime, streets are mislabeled because I'm not there, I'm missing turns and taking others too early, the car is jumping on and off the freeway because of streets running parallel to the freeway, etc. I think that dead reckoning is overriding the GPS signals some how or its jumping back and forth because....
Because what? Can you have a damaged antenna? Dirt? ( the cars been detailed twice) Antenna misdirected? Too much smog? I don't know. Some poor guy's system showed him in the ocean. At least I'm still on land.

Chick 47,
I have cured three nav systems by placing the car under the open sky and simply letting the car idle with the nav turned on. The position on the map would slowly move till the location was the dealership. This takes about an hour. Cured one by 15 miles and two by 1000 feet. Worth a shot.

__________________
Paul

Paulwho,

That is astounding! No one has come up with that solution before. You're right, it's worth a shot. Just curious, is that an approved diagnostic technique and cure?

Chick
You can do the location calibration, which "sets" your position at least for that moment. Yes, there is also a "setting" for the tire size, try to find that and make sure it is correct, this mainly affects the "dead reckoning" though, in normal operation the GPS system sets your location by itself.
Thanks for your idea Paul. I would think that it should learn it's position as long as there is free sky, whether it's moving or not, but your idea certainly is worth a shot, at least if he is receiving satellites. If none of this works I assume he has a bad new COMAND unit, I wonder if no one set a tire size (in the new unit) if it would act this way, I've seen this before where it said "P000/00-00".......If you see this Chick you may have found the problem.
Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

Thanks Gilly, we tried the tire calibration. It was set for the front tires like the manual said, but the dealer changed it to the rear tires and said it was all better. Of course the difference is inconsequential. Bottom line though, I have finally gotten management's attention because of these postings and the embarassment to them for treating it all so lightly. By the way, I am female and I sure hope that didn't impact my credibility with them. It has them thinking a lot harder now. I'm not giving up until it works.

Chick

I've never heard of this front v rear tire thing, maybe yours has different sized tires and it makes a difference?? Oh well I won't dwell on that too much, and besides as I mentioned, the tire input is used when the sky is blocked (tunnels, parking ramps etc). When the satellites are being picked up you should have a very accurate position based on GPS just like any other GPS receiver. If the screen definitely shows you are picking up multiple sattelites (at least 3 for triangulation) you should be accurate within at least 50 feet or so, usually alot better than that. I'd say if this is the case (you are receiving sat's) that the new COMAND unit is defective, it wouldn't be the first bad new one I've seen!

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

Gilly,

Thanks for the help and this could have been the first defective unit you have seen but...bottom line the comand system was calibrated in the English language, like UK, not USA. I took it to a different dealer after seeking out the expert, and he looked at the menus and instantly knew it was not the "American" version. I haven't had much time to test the nav, but my mileage "improved" instantly. I was showing 29 mpg on the surface streets right away. I guess liters calibrate differently than gallons and meters and miles do make a difference. I don't know what the odds are on finding something like this, but I'm glad it's over. Thanks for the input.

I don't see how this would affect the GPS not showing you in the correct location, I would reserve much for comment on if the GPS mapping is correct until you've had time to test it. I can see the mileage factor, although it would show this in the instrument cluster, not the GPS and the setting would be changed in the cluster also. The fuel consumption also would have been shown a liters per Km (unsure how this is abreviated), not mpg, so pretty hard to mistake what is being shown.
This would NOT be the first defective COMAND unit I've seen, I have seen several bad right out of the box.
It would be nice if it's fixed, but I'm skeptical, based on your description, that you'll stay on the map where you should be.

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

I can't explain it but the cluster did say mpg. I had checked the range on a little less than 1/8 of a tank and it showed a range of 463 miles. I think it just shows the number not an "m". When recalibrated it showed 305, much more realistic. My understanding is that the display is in US English but the calibration has to be matched to the display. The nav was calibrated by location, an exact point that this dealer uses all the time. It was dead on. The movement on the screen does lag slightly behind. I only drove about 25 miles but at least the turns were called out before it was too late to make them. Oh and sorry it was a typo, I didn't mean that you had never seen a bad system. I'm sure of it. Let me ask this though.. Since this is a CD based system, wouldn't it logically lag slightly as it tries to update? If it is trying to make some distance conversion from metric but place it on a US standard map display, it seems possible to cause a problem. You're right that it needs more testing but its looking hopeful.

I think the capabilities of the system are such that the COMAND actually has a better fix on the position than is cabable of being displayed on that small screen with a large (although more readable when driving) arrow cursor. And I agree it probably could be updated more often, there always seems to be that bit of a lag as the map area moves around on the screen. They have alot of features crammed into that box! Cost vs effect I'm sure.

Gilly

__________________
Click here to see the items I have up for auction at EBay

Click here to see a photo album of my '62 Sprite Project Moneypit (Now Sold)

I know nothing about COMAND, but will comment anyway.

If the unit was calibrated English units, would it read in miles/Imperial gallon? This will increase your virtual mpg by 20%, since there are 1.2 US Gallons in an Imperial gallon.

This might have added to all of your fun...

Ah, the good old days of looking out the window to determine one's postion...

Best Regards,
Jim