Navigation CD system is Lost! Can't find me

[Chick47]

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.

[Gilly]

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

[Chick47]

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.

[Gilly]

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

[Chick47]

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.

[Paulwho]

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.