Hi, I have found most of the posts on troubleshooting D2B errors. The main steps seem to be isolating each component, determining which is bad etc. Depending on location, you may need a loopback or similar type of connector to make sure the D2B bus isn't broken.

My problem is that I'm not sure where to start troubleshooting. I've had a problem for a while where I'll get "Navigation cannot be activated error" when the HU first is powered up. It's pretty random. The COMAND unit will appear to start up very slowly, then throw the Navigation error. If this happens I will have no sound or anything else. If I run diagnostics and see that the D2B bus is open. Usually I can reset the bus and the HU will come back. However, recently, what's been happening is that the unit will just power itself off. I'm able to eject the nav CD so I know it has power. It's just that the nav unit does not respond to the power button. Even turning off the car for a while won't always fix it. I'll also get the "No CD Changer" message.

One thing is that I had TeleAid originally but had the dealer code the D2B bus so that TeleAid doesn't show up on the bus, although the hardware is still there. I can't remember why I did this, and I'm not even sure my memory is correct. Maybe it's the TeleAid unit that's causing my problems. What's interesting is that when I run a D2B test, it doesn't show "analagous Bose" on the D2B link, which I'd expect since I have the Bose audio and amplifier.

I thought this might be a bad nav CD, so I tried using the HU without any nav CD, but still occasionally will get this error problem. With no Nav CD installed, it will usually be a "No CD changer" error condition.

I know this could be a defective HU, and I'm ready to replace it or get an aftermarket unit, Garmin, or something. However, it could also be a fuse, an optical cable or something other than the COMAND unit. Before I assume it's a bad HU, I'd like to try to figure this out. Can anyone tell from the error codes what component has failed? Is there a software update for the COMAND more recent than what I have?

Here's the data I get when going into diag/engineering mode on COMAND:

DIAG Errors are:


SAE Code Type

N1111 0x0190
N1112 0x0000
B1762 0x0000


Info about unit:


VERSIONS

Processors

FIS October 29, 2001
Copro valid
DSP 640000 130600
SW-Version REL_V06.30
Project OMS_U203

FIS

HW-Version 01.02
SW-Version 44.01
Production Date 13.04.05
MB-Number 2038273142
Manufacturer Bosch
Diagnosis ID 0501
Serial-Number 03549101

SH

Version info
Decode: V 5.21 release
Head OMS_EU_R SH: 2289 MCM: 2289
Mask tool 3.0d
SH Mask V01.02 20-AUG-1998
F: OMS_U203 Version 06.30
Comp: October 29 2001

Copro

Copro valid
SW-Version 30.01
SW-Date 25.11.97
Variant 01

DSP

SW-Date 640000 130600

NAVI
HW-Version Navi 1002
HW-Version CDROM 06113
SW-Version Bios 967.07.13:32:17
SW-Version Diag NO ROM
SW-Version Navi 287.02.09:27:17
Version Database 285.23.4:21:11
Version Map-Data 285.28.11:02:32

(I believe the following is with no errors..)

D2B
Serial No SW-Vers D2B-Proto

Handy 0000636207 35 00 PDK 2.5
T-Aid no no no
SBS 00110867 23 00 PDK 2.5
CDC 2633700 2002499 2.3
Sound 00738491 3.19.w203.7 02.50

D2B High Connection

PID 1 2 3 4
D2B-Address 00 00 F0 F0
Direction tx rx tx rx
open/closed cl cl op op
Con status 00 00 80 80

CD-ROM

SW-Version 061.13V3.1

Configuration

* Telephone (expand.)
* Star Guide OBUR
X (not checked!) analogous Bose


MY C240's PSE: Q682064800348IA06 3ES

 

what's up zitsky. any luck with the problems you had^^^^ i recently have been experiencing the same problem. the codes my car has is N1111 and N1112. these are the only 2 error codes i get. also when i shut the car off the command stays on even when the screen and the whole car is turned off. i can tell because i here a whining sound from the command system. i've been going crazy on find a way to fix this problem because my car has low miles and highly doubt that my command system is broken because everything responds correctly. i just need to know how you resolved your issue if u did?