Jasien139

Hello everyone, i have a question regarding a W212 E220 CDI 2014 facelifted that i have owned for a year now.

a month ago i took the car to a carwash and they have a habit of opening the doors and pressure washing the sills.
this way my door projectors got damaged and after a while i started noticing that the Navi, Audio and Tel. pages show "----" instead of the usual information.
one day suddenly it started working again but as soon as i turned off the car and turned it back on, it stopped working again
the volume buttons on the steering do work.
i somehow feel this has to do with the carwash pressure washing the sills?

can someone please give me some advice on what i can do about this?
i cannot take this car to the dealership as the country i live in has no Mercedes-Benz dealership to tackle this issue.

thanks in advance everyone,
ps. english is not my first language, please forgive me if there is something unclear.




​​​​​​​

CaliBenzDriver

You've landed in the right place. Your car possibly got water in the footwell area as reported.

You're gonna need to be your own dealership unless you can find an Benz specialist locally...

What's happening is for some reasons your Instrument Cluster is unable to communicate with some of the other modules.


> Actions:
1-- ​​​​​​You want to figure what modules are actively disrupted. For that you'll need to use a compatible OBDII scanner to read all faults.

2-- Are you comfortable taking things apart?? If so go ahead and clean both sides front footwell GND Posts after disconnecting batteries.

(Don't drain your main battery while working on and around your car)

Jasien139

Thanks for your awesome response!

tomorrow i'll ask a friend of mine who is a mechanic to borrow his OBDII scanner and see what i can find out and keep you posted.

on the other hand, do you know where and how can i get my hands on diagrams or manuals on how and where to find the ground posts?

Thanks in advance!

CaliBenzDriver

First thing first! Until you have an actual list of disrupted modules, you don't really need WIS diagrams from ebay dot com .... ALLDATA dot com Identifix and the like.

Given your issues, dealing with footwell GND posts right now is a valuable time saver. GND are located under up front carpet in both passenger/driver sides.

Are the carpets wet??

Take pictures to assess oxidation damage quality


++++ NAVI/COMAND:
Is the center console display working as expected or is COMAND unresponsive??

Jasien139

No, the carpets aren't wet as far as i can see.

as for the centre console, everything is working as it should apart from one thing that i totally forgot to mention. the analogue clock (is on the correct time) but if i change the time in COMAND (for testing) it wont change, earlier it updated to match COMAND but now it does not. for the rest, the clock works, displays the correct time, but no changing time thus.

its night time right now, i'll assess the situation tomorrow, will make a few pictures and keep you updated.

Thanks

CaliBenzDriver

Let's hope your COMAND Module not sick ($$$$) - Hopefully it's only CAN-B getting bugged down.

OBD scan will tell
🤞

Jasien139

Hello, CaliBenzDriver
i am very excited to tell you that it works! for now atleast...
so today when i went to the car to open the carpet i realised i am not up to the task because i dont have the required tools. i couldnt scan either because my friend is on a weekend trip.
so the scanning part i can do on monday and keep you updated. so with low hope i sat in the car and remembered i read somewhere on the net that i can do a soft reset of my COMAND by holding the ON button for 10 seconds. and behold the information showed up in the cluster!

i turned the car off, started it again, it still shows!
im going for a drive later and ill see if it still works.

i will still scan on monday and will keep you updated.
cheers

CaliBenzDriver

Instant relief surely's awesome - You've got a good shortcut.

A soft reset of COMAND got your cluster display showing audio data again.
​​​​​​COMAND was only soft crashed... lets see how long it will run before bugging again.

That will help us understand why only its CAN-B interface goes crazy (GND ? CAN-B ?) while central map display works fine.

Enjoy it for now

Jasien139

Hi CaliBenzDriver,
After reporting that it worked, i took the car on a drive, turned it off and on many times and it stopped working again.
this time however i do have a few more clues that might show us what the issue is and i also scanned the car.

So first thing i noticed on Sunday:
- Soft resetting makes the COMAND show up in the cluster, and the analogue clock now reacts to COMAND
- Turning the car off and on, Makes it stop working!, weird isnt it?
- after restarting the car if you immediatly soft reset again, no difference.
- but lets say after a few minutes soft resetting, it works again! untill i restart the car

i wouldnt blame the cluster however, because the cluster has nothing to do with COMAND not being able to change the analogue clock right?

now the things i found while scanning:
- Driver side SAM (N10/1) = B1E211B ( Buffer battery malfunction) aux battery malfunction did show up on the cluster but that cant be the reason for the COMAND acting up right?
- PTS - PARKTRONIC (N62) = U015587 Communication with the instrument cluster has a malfunction. the message is missing.
-Rear SAM (N10/2) = no errors
-Audio/COMAND = Communication with the gyro sensor has a malfunction. (Active Error) | The bluetooth antenna has an open circuit (stored)

so this is all the info i could gather so far, what do you think it could be? should i try replacing the aux battery? not sure that thats causing it, my brake hold however doesnt hold since the battery went out.

hope to hear from you soon

CaliBenzDriver

​​​​​​Good detective work with scanner + research

When you consider this thread and your excellent fault collection your CANBus-B issues seems centered around DRIVER FOOTWELL GND POST!
-- We are going to quickly jump on fixing that first before anything else.

AUX batt may be collateral damage but not cause. Test it out of circuit to see its resting voltage.
Is it significantly below 12.5V - Consider date code, charge it - Keep/change: your call. No rush unless proven guilty.


By fixing goofy COMAND GND supply, you will actually get all things CAN-B working with lower latency.

MB faults are layered, meaning the more you ignore them, the worse things get until progressed into battery drain, no start, limp-mode...

When in chaos... "Module Resets + Car Reboot" are a great way to get back to base line before fixings root causes - Usually solderless, poor GND, water egress.
✌️

+++ Driver side VIP GND fixing:
Disconnect all power!
Clean painted GND + oxidation (DeOx...)
power up vehicle
scan/reset all transient/power faults
​​​​​​Go drive 20Mi
Scan again then Post results

How is COMAND doing: normal or freezing?

If no joy, we'll focus on your CANBus-B
🤞

vich3

Calibenzdriver
Your support, encouragement and assistance is beyond reproach.
Members on this forum are very fortunate!!!

CaliBenzDriver

You are right, we like making progress, hate non-sense and poker faces. I like all my gear to work right, I mean really well.

These great cars are super well built to run predictibly. With just a few tweaks we can improve their driveability back to normal.

Running engines ridiculously low on oil compares to bottlenecking gateways with wonky modules. This creates all sorts of opportunities.

We still have a few more Easter-Eggs discoveries to make before all modules can network smoothly. The more I understand, the more I can focuss on module performance without available code.


I take this opportunity to kindely thank Master Surya for all the outstanding magic he makes happen around here - @S-Prihadi has been closely involved in every steps helping me make sweeter lemonade with my car. Surya knows first-hand the outmost importance of measuring true engine performance, electrical circuit parameters, limitless aspects from A to Z all the way to the jacked up squeaky wiper arm angles.


Like united servicemen, we win when contributing efforts together. So again I am happy to help you and other good ppl when possible.

Jasien139

Hi CaliBenzDriver,
Okidoki noted, ill get working as soon as possible on the Driver footwell GND Posts.
Oh and i pulled a pdf that might help me locating the GND post.
after that, scan + take it for a drive and see how it performs.
ill try to do it this week and keep you updated

COMAND is doing fine, no freezes.

thank you very much for your help and kind advice, will keep you updated asap

CaliBenzDriver

right side cabin GND locations....
Deal with above FOOTWELL and the left side as well. They are both equally amazing to clean.


> NOTE!
-- Having good GND ensure minimal glitching power through the weak connections created with solderless pins.

-- We precisely do NOT WANT ANY FLOATING GND, meaning all voltages must be reliably referenced to the same zero volt called chassis/engine ground.

-- Floating GND voltages are an excellent source of unnecessary CHAOS... we are going to fix this religiously well.


RHD vs LHD :
I recall COMAND grounds on the same side with Front-SAM, the computerized Pwr Mgt. fuse box.
In the US LHD this means F-SAM is on the driver side, where top VIP Modules come to source their GND from.

> Footwell only:
Do a good job on both L/R sides if you will.
Leave the seat beams GND or back end GND or front end GND for later.
✌️

Jasien139

Hello @CaliBenzDriver ,

i am sorry i disappeared for a few months. there was a lot going on with work and after that my marriage planning etc..
All went well and due to all the work and other things of my mind i forgot about the car issues.

i do, however, have an update regarding the GND Posts.
i have checked all of them and everyone of them were clean and in top condition. also no water or any sort of wetness spotted under the carpet so we can check GND post off the list.

however i have returned with a much grave issue.
a few things to note:
i still havent replaced the aux battery that i mentioned earlier so i was driving with that error all the time.

after my car sat for 2 days, today i started it and saw that my COMAND didnt even turn on!
earlier we know that the cluster wasnt receiving info but now that combined with the COMAND fully failing it seems.
i checked with the bluetooth on my phone and it didnt connect thus, its not the display that failed. rather the issues seems to be with the unit itself?

also i noticed while driving at night, all the lights on the COMAND unit are off due to the unit itself being off. BUT the ON light on the Round power knob kept slowly blinking.
after coming home i pulled fuse#11 out of the fusebox to see if that may have been burned but... i dropped the fuse while pulling and now i cant find it. so off to the store i will go to buy a new 7.5 A fuse.
i also searched the internet and people seem to say that if the battery voltage is lower than normal the COMAND stops working.
my Main battery seems to be fine as the car starts fine.
could it be the aux battery affecting my COMAND?

issues know so far of COMAND:
-dash not getting COMAND info
-dash gets info when COMAND gets reset (10sec pow button)
-COMAND display sometimes turned off and on instantly when starting the car and driving it.
-and now the whole darn COMAND failed.

what could i do in this situation?
i am out of ideas and my head isnt working. after spending 2000$ on new wheels for the car. the last thing i wanted was more costs!

i am looking out @CaliBenzDriver for your wise advice
p.s. forgive my typos, as i am typing while being sleep deprivated.
Kind regards
Jasien139

juanmor40

First thing: fix any battery issues.

These cars do not like low voltages a single bit.
the command unit is just a computer running Windows CE if I recall correctly. If by any chance a low voltage produce a "wrong step while booting" it can get into a boot loop, and all beta are off.

Let us wait for Cali advice, but low voltages are going to mess up your car

CaliBenzDriver

Well you know me: we need testing + evidence to anchor solid decisions.
After "nice and easy GND campaign" things are only going to get more difficult.


As Juan said, think about replacing the bad battery soon and use a tender to keep batteries in shape as needed.
AUX is mostly resting unless Main gets low then AUX get drain supplying it's VIPs.
Long story short keep MAIN tendered! Disconnect batts when MB not unused. CAN-B Modules vampirize MAIN dry with poling for safety lock + the rain sensor condition.


You said you cleaned footwell GND was good. I take your word for it, great!

-- Now you can scan your chassis and hope for luck - This kind of flakey issue doesn't get reported squarely. Let's see what kind of low-voltage disruption faults show up if any.

-- Next you can try to trace a schematic to understand what can make the knob blink crazy.

-- Next scope (or DVM?) the power supply (both the "+/-" ) from modules that are not working.


Working on Mercedes, we run out of shortcuts and simplicity very quick. Just identifying superseded part numbers requires skills + intelligence.

I just hope your footwell GND are as good as you say they are.... You can do some direct bypass jumpering as a module power supply test.

Jasien139

Thank you Juan and Cali, glad to hear from you both,
i'll bring it to a garage to do a full scan of the car.
Next, i'll replace the AUX batt as soon as i can find it in local stores (otherwise ill have to import)
Meanwhile i am also going to do a test on the MAIN batt to see if its still in good condition.

i'll update with what i find as soon as i can.

kind regards
Jasien139

Jasien139

Hello Cali, sorry it took me a while to update, there is alot going on right now.
anyhow, on to the results:

I did the chassis scan and here is what i found;
Now i did also notice something else:
When searching for a unit my car isnt equipped with, it usually just says "No response".
And it said the same thing for:
HU (head Unit Control Unit) = No Response
isnt this my COMAND?

Since my last message the car has been sitting because i had no time to look into it.
anyhow, yesterday i went into the trunk to look at the battery part number and im about to import one very quickly so we can get on with diagnosing this car quickly.
the AUX batt is a 12V | 12Ah (A 000 982 93 08) but the only replacements i can find are 12V | 13Ah. would it be okay to replace it with higher A?

I also noticed a bunch of other faults which went away after clearing but a few stood out.
these too went away after clearing but was a bit worrysome to read.

i have absolutely no idea on what to look for now and how to proceed. is my head unit dead? is it the aux battery? no idea. i guess ill have clear answers when the aux battery arrives and is installed.

in the meantime i look out for your wise advice Cali, you are my only beacon of hope.

Kind regards,
Jasien139

CaliBenzDriver

Well to try and sum this up... it seems that your:
-- Instrument cluster and
-- COMAND HU and
-- CGW gateway
are having an argument and are in disagreement about something.

Any chance a foreign spare module got introduced??

The battery need to be tendered as a active vampire is reported as fault. This drain is responsible to kill Main/Aux batteries.

S-Prihadi

Jasien,

When you scan the car, make sure there is a power supply or battery maintainer keeping battery NOT running deficit.
At Ignition ON engine OFF, if M276 engine it will consume 11-12 amps, without accessories running....just related modules waking up due to the ignition key position.
So you need at least a 15 -20 amps battery maintainer set at 13.2Volts as good enough.

Every time you scan the car, make sure to read the DTC is a stored/historical or current ?
Power loss can do a lot of weird DTCs and including CODING is wrong yada yada.

The sound system , I would not call it COMAND as I do not have navigation feature....will be turned OFF by Front SAM N10/1 computers at 11.3volts main battery voltage.

Get your AUX battery connected and properly charged and make sure your main battery is healthy, and then you troubleshoot further.
Otherwise you may end up getting tricked by low voltage situation.

Good luck.....

Jasien139

Hello CaliBenzDriver and S-Prihadi,
it has been a while since i reported back.
in the meanwhile, my COMAND Head unit died and only at night the power button blinked slowly.
while i haven't replaced it yet, due to financial restraints (i can only afford a second hand one, but the dealer wont install it and i don't know how to do it myself as i heard there are anti-theft measure that needs programming etc..)
A new one at the Mercedes-Benz dealership in The Hague, NL costs around 3000 Euros.
I contacted a few companies in the Netherland that i can mail my COMAND in for fixing. as they claim they can fix it, so i will try this method first.

i want to thank you all for your kind, detailed and informative explanations and guidance; especially you, CaliBenzDriver.
i have more work to do on my car, and i will make a post soon regarding changes to the suspension, as i don't want to change the topic of this post.