W204 Command Screen Opening Issues

[xtremem23]

Having a bit of a nightmare at the minute in regards to the command flip up cover and screen in my C180 2010.


Link to show whats happening:

https://www.youtube.com/watch?v=KjvjCMNr_ls



Symptoms:

1. Ignition turned on
   
   
2. Cover opens fully.
   
   
3. Screen flips up, MB logo is displayed.
   
   
4. Doesn’t proceed to boot to display the command warning when driving babble etc.
   
   
5. Screen flips down and cover closes again.
   
   
6. Audio remains on with limited functions at steering wheel.
   
   
   
   
7. Press the button on top of cover.
   
   
8. Cover opens and screen will flip up but this time remains up but screen is black.
   
   
9. Audio remains on with limited functions at steering wheel.
   
   
10. Will stay like this until, key is recycled or button is pressed to close.
    
    
    
    
11. Whilst the screen remains open, pressing button on cover will illuminate the display and show the MB Logo or radio channels and then returns to the black screen again.
    
    
    
    
12. But at times I can get into car turn the key and everything is fine, command works as normal?
    
    
    
    Items I have covered in checking so far
    

1. Fuses
   
   
2. Remove unit and checked wiring connections
   
   
3. Reset system
   
   
4. Checked battery voltage
   
   
5. Remove battery leads for hard reset
   

There has been threads on this before but just seem to stop without any definitive answers as to what actually is causing this to happen.

Like, why do people ask for help/advise and then find the solution either on their own or a third party and not report back to help other, it’s really a thing that annoys me to be honest and those people should be banned, lol……rant over.

This used to happening every now and again and a simple key recycle would have resolve so any help on the matter would be greatly appreciated before I go and purchase a new screen etc. as I’m not 100% sure that it is that due to that it sometimes functions as normal or by pressing the button illuminate the screen fine.

Thanks

 

[L John]

Can't help with why it's not booting up but the button to close it (step 10 on your list) is just below the bottom of the screen along with the tilt adjust button.
You said you have checked the battery voltage, what was it?

 

[xtremem23]

L John,

Thanks for your reply mate,

Main battery voltage was 12.2v car off & 14.5v car running so alternator seems to be charging ok.
Battery in boot was 13.8 constant when car is running and when its off.

I've noticed today though,

When I got into the car this afternoon, screen flipped out and then back in again as per expected, so I pressed the button again and it came up but screen was black so I left it in this position.

Took car for a drive and was idling in car park for approx. 10 mins. with screen in the up position but black.
I decided to recycle ignition, low and behold the screen came on a comand booted normally....????

Now I'm thinking that to me it seems that it is a power/battery issue.

I primarily do short journeys and have lights on auto and looking back I replaced the headlight bulbs with nightbreaker as standard h7 bulbs were to me terrible and dim.

It may be that by completing short journeys isn't giving the battery enough time to recharge etc. and this is causing an issue when comand is booting from a cold start up.

What I am going to do now is::

1. Let the car sit for a period of time.
2. Before starting check voltage at battery to see what its reading because I'm nearly sure at one point I done this and battery was reading 11.8v but don't remember if command booted normally or not at this point.
3. Record reading and then cycle key
4. Check if command functions correctly
5. If not, take for drive or allow to idle
6. Check battery voltage and record reading
7. If over, 12v then recycle key
8. Check if command boots correctly
9. If so, replace battery or charge battery outside of vehicle
10. If not, back to square one and pull hair out.....

Any thoughts that this sounds sensible or I'm I just over thinking

 

[L John]

Sounds like a good plan.
Mine comes up and goes straight back down if the battery is too low, even though it starts fine. Usually when I've been watching videos while the wife is clothes shopping.
Before that it says command will shut down in 3 minutes unless the engine is started.
I found it's not a good idea to start and then stop just to stop the warning.
Mine has never opened and just shown a black screen so I'm guessing there's more to it than a low battery.
Also when my battery was low I was getting random errors on the dash before I found the battery was too low and had to call the RAC (that was before I decided to buy a jump starter pack, never needed it since but nice to know it's there)

 

[LostKiwi]

Sounds like a fault on the ribbon cable to the display perhaps

 

[xtremem23]

Lost Kiwi,

Interesting theory in the ribbon cable, can you explain the reason behind this suggestion a little further please so i can understand it better, or is there a check that you can describe that I can complete to rule out ribbon cable etc. ?

I've no trouble in pulling this apart as I have done twice now anyway.

LJohn,

Yes, if in car with engine not running and system on then command will display a shutdown warning.

I od get random errors with lights form time to time, always seems to be the rear left brake/tail light for some reason or another but when I check it, its ok and the error goes away which is a bit strange, this has got me thinking is there a "gremlin" in the canbus somewhere that taking the ****.....lol.

 

[LostKiwi]

You have some functionality so therefore Command is booting but the display is blank.this suggests that the basics present but not displaying.
Had almost exactly the same issue with a Philips radio with a popout screen.

 

[xtremem23]

Lost Kiwi,

Don't think it is the cable tbh as if it was then why sometimes does it work and others not ?

If it was the cable, then it surely wouldn't work at all to my best of knowledge.

When it doesn't work, i.e. screen opens then down again and I press the button to open it, it only displays the MB logo, then blank, it does not as stated above go onto the "Comand warning whilst driving" display so hence the reason that I believe its not booting up at times, which would also rule out the cable perhaps as scrolling knob does also not function.

Is there anyway I can test the cable perhaps to rule it out ?

thanks for the suggestion none the less though.

 

[L John]

LJohn,

Yes, if in car with engine not running and system on then command will display a shutdown warning.

I od get random errors with lights form time to time, always seems to be the rear left brake/tail light for some reason or another but when I check it, its ok and the error goes away which is a bit strange, this has got me thinking is there a "gremlin" in the canbus somewhere that taking the ****.....lol.

It shows the shutdown warning and closes when the battery voltage is below the set limit to prevent the battery getting too low to start the engine. Low battery voltage will show phantom errors too.
With the engine running you said you had 14.5 at the main battery and 13.8 at the rear battery.
So when running, COMAND should start correctly, even if the battery is in need of a good charge.
As Lost Kiwi says, a ribbon cable moves each time the screen is raised/lowered or the screen angle is adjusted.
If you have a break in one or more of the wires, it can get an intermittent connection because when it's broken, it's still very close and can make a connection one time and not the next time.
Not sure that would affect the knob function but possible I guess. Certainly could be the cause of a blank screen.

 

[xtremem23]

LJohn,

100% not the cable, didn't make sense to me that it could be the cable in my instance, but I understand that the cable moves etc. just cant see how the cable would display the symptoms I was seeing, anyway good advice and worth keeping in mind moving forward as just because it may not resolve my issue it may others.

So, update:

Got into car this morning and cycled key, comand did not come on and screen cycled as described as before. opening and closing etc.
Checked battery voltage, 11.8v just as I thought
Took the car for a long drive today to boost the battery up, did not cycle key nor comand whilst driving, stop after bout 40min drive, key off, checked voltage again, now reading 12.64v, excellent a healthy battery.

Recycled key, and comand functioned as normal and after various stop starts throughout the day continued to do so.

So I'm 100% convinced (at the minute) it's a power issue, just have to work out why the battery dropped from 12.3v the night before to 11.8v this morning.....hmmmm.

Any idea's ?

NOTE:
Also, I can see the logic in what you say about when car is running and I'm getting the 14.5v when charging.....and I agree lol.
But for whatever strange and wonderful reason it didn't and that's baffling to be honest lol

 

[xtremem23]

@LostKiwi

Can you help me a moment please, i'm trying to get my head around this a little bit more but i'm getting sightly confused about charging voltage etc.

Yesterday i left the car running (idle speed) for approx. 20-30 mins and noted that the charging voltage was a steady 14.1v on the dash display.

Switched off, left for 15 mins and took car for a drive, whilst driving the voltage, 90% of the time remained at 12.6 with it only going up too a max of 14.5-8v when adding additional load into the circuit i.e. switched AC on at full, lights and when braking, after braking etc. voltage returned to 12.6v and was more or less steady.

This morning, after leaving car overnight, got into car, keyed to ignition position 1 and brought up voltages on display, 12.3v was displayed, started car and immediately voltage remained at 14.3v till i reached my work place, 3 mile drive i may add.

So the questions are,

1. Is it because i had left the car running for approx. 20-30 mins and 14.1v was being supplied and the battery had been topped up to the point that when driving the alternator only needed to supply minimum voltage unless when i switched the AC on or braking that the alternator had to regulate/increase the voltage output which brought it up till 14.3 ?

2. Should alternator be producing the 13.8v - 14.8 volts all the time ?

3. Do you think that the alternator is fine or on its way out ?

4. If it's on it's way out, then why under additional load would it increase output ?

5. Would the free battery/alternator health check at kwik-fit be of any benefit ?

Thanks

 

[LostKiwi]

I'm not sure but if you have a computer controlled alternator once the battery reaches a charged state the alternator will be switched off.
Traditional systems charge constantly and when running will operate at 13.8 - 14.4v typically.
From your description it would seem yours may be computer controlled and if so it's normal behaviour.

 

[xtremem23]

Just want to give the forum a quick update in case any others have or are having the same issue.

In my case,

Turns out that the potentiometer within the display flip up mechanism is on its way out and seems to be giving out to much resistance which in turn is making the car think the display is being restricted and closes again.

It's a small part but finding one is the hard thing, it's not a serviceable part as far as i can see, there no Mercedes part number on it, as its part of the whole unit.

hopefully come across a scrapped one, the hunt goes on.

thanks for all of the advice.