Thread: Multiple issues after DIY Stepper motor/ control arm replacement.

My Car is a 2002 w203 Coupe, which I have recently completed the following retrofits.

1.Comand 2.0 2004 version with Sat button.

2.Voice control system.
a.Both have been version coded by my local dealer. The Comand was working flawlessly, the Voice Control was another story, which doesn’t work as I would expect, can’t see the contact list or stored stations.

3.Digital Climate Controller, no other parts were added to the stock 6 stepper HVAC.

My issue started with repairing one of the Stepper motors and broken control arm (Passenger lower flapper). Since I had the dash taken apart I also swapped out my old climate control for the digital climate controller. I can normalize the system if the old unit is plugged in, but the digital unit will not stop flashing. But it seems that it works correctly when I set one side temp to Hi it blows hot on that side, set the other side to Low and it blows Cold on that side. When I turn the directional dial to select where to have the heat positioned it works on both sides expected.

The Dealer informed me the problem was due to testing the system before reinstalling the upper console switches insert the key and starting the car.), after getting everything back in place I noticed that I had an SRS fault with the dash light lit and the center display screen showing the fault. Also the car alarm and tow alarm switch stopped working the othger two (Door Lock and Traction Control).work fine, as did the Comand.

I went to my local dealer to see if clearing the fault code would fix the SRS issue which it did. But the dealer also informed me that I had multiple HVAC codes which I expected since the Digital controller is designed for the 10 stepper motor HVAC not the 6 which is stock in my Coupe.

I asked about getting the controller recoded so it would work but I was told that was impossible, which translates into we don’t know how and we’re not going to do the research to find out.

Here are my remaining issues after the fault codes were cleared which I hope to see if there are answers to fix these issues.

1. The Comand unit will get into a state where I can’t switch screens none of the left side button or upper buttons work, none of the number keys work, I can use the button on the right to move up and down the menu but pushing the button will not execute the selected menu item. The volume button works fine and I can still control the phone, and all other functions through the steering wheel.
If I remove the 6 CD caddy, eject the Navi CD and remove the v60 CDMA Phone from the cradle power off the Comand remove the key wait 10 to 20 seconds and power the Comand back on it will again work but only for 2 or three minutes and only if the Climate control is not set to Auto Mode.

2. Since My dealer has not a clue on Retrofit coding:
My question here is what can I tell them on coding the digital controller to have it not throw endless fault codes? When they came out to tell me what they found they must have had at least 10 pages of fault codes all pointing to the climate system. I’m assuming the climate controller is causing all or most of these issues, or could they have cleared version coding when they cleared the fault codes and the command, Voice Module, Phone system, Tow/Alarm, climate controller all need to be reprogrammed?

Or do I just need to forget the Digital Climate Controller and replace it with my old Climate Controller and have the Fault codes cleared to fix all these issues?


Thanks for any help here

a) COMAND unit is faulty.

b) I converted 580 to 581 and I noticed that there is more than just 4 more motors.

The differences 581 gives.

- external sun sensor in middle of vent grille on hood
- pollution sensor
- wiring harness for both above

- 4 additional motors
- control lever kit for new motors and old motors
- blower housing for 581 with charcoal filters
- filters

- control module for 581
- stepper motor control harness

That is why you get so many problems.

I've read that the digital Controller can be coded to disable the missing Motors and all the other items you've listed. I took my car to a different dealer today they checked on the version coding which was not done correctly. Coding fixed Comand fixed so not defective, replaced the Digital Controller with the old unit everything works fine.

So what I hope to find out is where in the Star software would the Digital Controller settings get changed to disable the missing items on the HVAC.

Turn off the missing items and no fault codes. The dealer tried to fined where to do this change but no luck, and since they didn't charge me to update the version coding I wasn't going to press my luck.

If you dont input the dimensions of the tires into the COMAND it will do the same thing as though it is broken.

Thanks for all the help, this forum is invaluable with so many questions

I think I wasn't 100% clear on what information I've been looking for with my question, much to much rant about my dealer and not getting to the point.

The Comand issue is resolved it worked perfectly before I tried to add the climate controller that was not designed for the HVAC equipment installed in my car. Second dealer recoded the comand and voice controller all works 100%.

But if I want to keep the Digital Climate controller, I need to find out if what I've read that using the MB Star diag system, this controller can be reprogramed to disable the features that my HVAC system does not include, therefore stopping the fault codes and allowing the system to be normalized.

thanks again for all the help everyone here provides...

Sorry again...

I left out the most important thing I need to get the Climate Controller reprogrammed. My dealer could not find where in the MB Star Software tis could be done.

If this is posable I'd need to know the menu path to the area that the reprogram data is entered and what needs to be changed and saved.

Thanks again...

and as the movie line goes Obi Wan Kenobi you're my only hope!!!

There are only SPECIFIC part numbers which allow for this notional upgrade. Those particular part numbers are tolerant of the problems you have been having.

I personally dont have a list of them but I know that it has been listed many times in forums 4 or 5 years ago. It is just a chance event even then.