2012c350

I tried a search here and don't see anything about this. If so, please point me to any existing thread. Searching the internet shows a bunch of people with the problem of a small plastic shaft breaking inside the knob that prevents the turning of the knob from doing anything. Being that mine was working, but not always responding to turns (sometimes a single click/turn wouldn't work...but then another click would jump 2 menu items ahead) I don't think mine is a broken shaft issue. It seems that over time the clicking wasn't being responded to until it finally quit altogether. This makes me think it might be a contact problem? Thoughts? If so, is there something inside the knob where I can clean the contacts? Also, any good links on how to remove whatever I need to remove to get the knob control out? I see many videos on disassembling the knob itself, but nothing on removing the component from the center console (for a C class.) Thanks!

xEryx

It broke, mine did too.

2012c350

Are you saying the shaft broke? If so, why would it have been working for several weeks but not always responding to the turn each time... I would've thought that a broken shaft wouldn't slowly quit working but would abruptly quit? In either case, I need to get the control knob out, so any pointers on how to remove what I need to remove to get to it? Also, did you fix it yourself or take it to the dealer? I'm reading that this could cost ~$1000 if the dealer fixes it.

xEryx

It was probably slipping and catching on sometimes randomly. My COMAND knob does the same thing, it is probably breaking. I had ELW when mine broke so dealer replaced it, you can buy the shaft and replace it or replace the whole part for $200sh.

2012c350

Thanks. Any info/ideas on how to get to the part. I'm hoping someone has done this and made a video. :-)

w204_racing

happened to my car, my fathers a Mercedes tech and with the help of youtube took 30 min. The part is very cheap

dchar

This vid should be helpful:


My COMAND knob broke a while ago, but I haven't found it worth fixing. It still functions when bumping the knob instead of rotating it. I can't believe it broke since it was barely used. It was quite dumb of Mercedes to make this part break so easily.

timlippold

You can buy part online. I had my dealer do it and the price was reasonable. I think around $300 all in. $1000 is a total rip off.

shotgun_banjo

Just buy a $6 gorilla glue. Glue it together then let it dry. After that get a piece of toothpick cut it to size and gorilla glue it on the 4 sides of the shaft indentation and make sure to soak the toothpick with gorilla glue. let it dry for 24 hours and you just fixed your broken shaft for less than $10. The pita is getting the cable unhooked below the center console. You need to push towards the passenger seat to unhook it. I have done 8 of these already and after you do 1 it is just like a piece of cake. Watch the youtube videos and it is the best instruction on how to do it. You can also buy the machined alum. shaft but i think it is over kill and what else will you lose if you gorilla glue it. I fixed one for a guy and he said he will pay me $200 to fix it and I told him just buy me lunch and he did buy me lunch THEN paid me $200 which is still FAR cheaper than the $850 the dealer was asking him for. That was 6 months ago and all the fix I did was the same and nobody has called me back to repair it again.

shotgun_banjo

Sorry I think without the rotation function of the knob it is utterly pointless to have. Do the fix and you will be happy. If you Navigation you will not be able to use the nav properly without the rotation function.

dchar

Yeah...I don't have nav so the knob is pretty useless whether it's functioning or not. Haha

2012c350

I bought the shaft yesterday for $29 (aluminum one.) Still need to figure out how to remove the console. The video posted above is the type of console I keep finding. That's not what the 2012 C350's looks like. Guess I'll just figure it out myself and make a video for the next person. Hopefully I don't break any plastic... If all goes well, $29 and some of my time will be worth it over $1000. :-)

dchar

Fast forward a bit and you'll see how he removed the center console for the other more common style.

2012c350

Awesome! That is exactly what I needed! Major thanks!

Schaun1911

Hey man did you get to fix your knob? I too have a facelifted w204 and Im stuck at removing the knob since the knurlings different

nelson g

Here is the link and the part you will need with how to replace it, hope it helps.

https://www.ieworksusa.com/collectio...aluminum-shaft

2012c350

No, never got around to it. Last week I just happened to come across the part that I bought for fixing it. Car is in the shop right now (wouldn't start because the Key recognition unit quit working.) . When it comes back from the shop in a day or two, I'm going to replace the knob so will report back.

drgraves

My 2012 E350 Cabrolet has a broken Comand Control Switch.
Does anyone have a video or written instructions for removal of the Command Switch? There are several videos on line but they do not cover my year and model. I am clear on the repair of the switch from multiple posts once I remove it from the console.

MysticMan

My knob is clicking on rotation but the rotation does nothing. Trying to understand if the shaft is broken or not when the clicks are heard.

Duncan Maclaud

mine stopped working. it doesnt even show on the display. i removed the command and realised the shaft was intact. i have even replaced the knob but still not working. any other DIY apart from replacing the knob?

Odd Piggy

When you say ”replaced the knob” does that mean you replaced the whole Comand unit?

chabbs93

I wouldn’t waste time trying to fix it. It’s a complex little box. I ended up buying one from eBay that was used from a totaled car. It has worked 5 years since. I think it was only 50$ on there used.

Duncan Maclaud

yes I replaced the whole command knob after I discovered the shaft wasn’t broken. I have done three replacements and still not working

Duncan Maclaud

replace the knob

CaliBenzDriver

You are saying you have replaced the whole knob module with no improvement.

Then you want to scan the car to see if COMAND reports any fault bugging it.

COMAND may simply have a poor GND connection
or the unit may require internal repair.