It looks like we have got the cd/nav system working. We found upon reinstalling the unit the comand head would stay on after the key was removed. You can hear the cd player shut down for a second then restarts again.

The radio's power button can turn the radio off but with the key out all things should be OFF. Please help...TNX

 

A Little more info on what you were doing in the first place would be really really helpful........

If you radio remains on when you turn off the key, it is most likely the D2B wake-up is not connected. Check the connector going into the comand to make sure the brn,brn/rd wires are making a good connection.

 

The original comand system had this cd/nav error problem radio. The MB dealer wanted $4500 to fix/replace the system, but we were able to get an exact rplacement I installed the system and it appears to work OK. The only thing I now see is what I said before.... Radio goes off when you pull the key but somehow after 30 seconds or so you can hear the cd player begin to start up again. If you push the pwr button the radio can be turned on or off, and that is the issue. Why am I getting power to the comand system when the key is removed.

 

It's getting power when the key is removed because it's designed so that you can press the power button and operate it when the key is removed. Modern cars don't have anything actually switched off when the key is out. They rely on the the computer networks (CANs) to turn electrical consumers on and off with signals. The wake-up/go-to-sleep signals are quite complicated interactions between the CAN-B bus (body CAN), CAN-D bus (diagnostic CAN) and the digital fiber bus (D2B until 2004 and MOST later). If your connections are all good, only a dealer or specialized independent with the proper diagnostic equipment can determine why the CAN is not getting the sleep signal or why the COMAND is not getting the right off signal from the CAN or SAM. For a flavor of what's involved, see:

http://www.babcox.com/editorial/ic/ic030538.htm

 

That basically is what I said. Only the 3rd grade version....

 

Yep. But the OP seemed to need a second course.

 

Well...we got it back into the car and believe it or not...everything is working.

Everything is working but the nav system is dumber than a stone. Why? It calculates the destination and takes you via the land of nod. What's wrong or is normal for the 2003 model? What to do ?

 

Carl066,

Check your COMAND manual; and if you don't have one,, download it from http://home.earthlink.net/~phdwebsite/comand_manual.htm

It likely has to do with your route preference settings.

 

Skylaw,
Went to Philadelphia and tried everything possible that I knew to get this thing to keep us on RT95 S to the PA Turnpike...but all it wanted to do was get us onto some back road. When coming back it took me 40 miles out the way before I found any signs that made any sense to me. My trust in the this nav system is dimming. What's a body to do?

 

Best advice I can give is what I gave in the prior post. It sounds as if the route options (preference) menu is set to avoid interstate highways, and possiby toll roads. See page 141 of your COMAND manual. "Fastest Route" and "Shortest Route" settings can also make a large difference in what the nav system selects. Even if interstates and toll roads are not excluded, if you have selected the shortest route and it is is just a tiny bit less mileage than the fastest route, that's where it will take you. It just does what you tell it to do.

You can also review the route the system selects before you start driving, after it has been calculated. If it isn't what you want, change those settings and see what then results.

The owners' manual set isn't easily digested in a casual read; a careful read will help you enjoy your car much more.

 

Thank very much for your input. I will continue to work with this system for a little while longer. Like most things...it could be the operator!