VBaboli

Hi all, yes, I believe my 2010 E350 is possessed.
Left the car at friend's driveway for about 2 months, started up fine, drives fine but, after a few minutes, the problem starts, lights on panel such as headlight, tire, break, fog light etc.. go on for a few seconds then turn off, also the AC, fan, radio, GPS turn off for a few seconds then turn on, vipers too. I have seen the clock also going backward. Car drives fine while all these are happening. If I turn the car off while these are happening, I wont be able to lock the car or start again for a while.
The main battery is over 7 years old, aux battery not sure how old. I have about 110k miles on the car.
Have you seen this phenomenon at all? is it my battery, some computer module or just possessed?
Thank you for any help.

DeTh

I'd get the battery tested, that's probably the culprit.

up_too_late

Yikes. The first thing I would do is disconnect both the main and aux batteries, charge them both, then reconnect them. It's free and easy. I've had a electrical gremlins due to weak batteries and had to have them both disconnected to reset the control modules (disconnecting individually did not resolve). You've gotten your money's worth out of the batteries so replace them ASAP and save yourself the headache and worry.

VBaboli

Last night, when I parked the car, it would not lock doors and I had to use the mechanical key, this morning, as if this is not the same car, started right up, lock/unlock doors. I am in Birmingham Alabama for another two weeks, only know pepboys around here so will take there today to change both batteries. MB dealer is a bit too far, unless you guys recommend me going to dealer, I rather not.

S-Prihadi

Was all these after a big rain ?
How long have you owned this car ? I mean how well do you know the history of the car ?

CAN BUS junction connector ( like a distribution connector) being wet can also cause funny-funny weird things

VBaboli

yes, it was after the big rain but this car has been in big rains before. I had this car since 2014, has been good so far. The batteries are def old but where is that CAN BUS located, can I check it out myself to see if is wet?

S-Prihadi

W212 is the same, depending on which CAN BUS channels, its at the LEFT and RIGHT side.
Best start at driver side.


Leak developed and accumulate over time.

VBaboli

Did you attach a picture, it does not show.
Found some post here: CAN BUS TOPOLOGY - MBWorld.org Forums
A PDF was there including the details.

VBaboli

Lifted the floor mat and there it was, water there is no drain??? I am not in my home there is no shop vac here.
If I get the water drained somehow, I still need to dry things that I can not even reach. Which shop even does these things?
I youtube video is very detailed, I can not do that here away from home.
UPDATE: Driver side is dry for whatever reason, ripped the floor out on passenger side and took a round plastic out so the water drains, not sure why it was there to begin with, I may not put it back. Dried water as much as I could and left a 1500W blower heater there. Will see in a few hrs if get any better. I will still change the battery later today.

juanmor40

Check the roof drainage along the A-pillar, it must be clogged with leaves or dirt. Once the water stop running, it starts leaking into the cabin.

MB --> fish bowls when the drainage is not maintained/checked frequently.

Dry it as soon as you can, and as dry it can be; otherwise, you are bound for more damage (harness/pcb board corrosion) and $$$ along the line.

For the driver side, 1 - Open Front-SAM and not properly closed:
2 - Windshield replacement
3 - Incorrect positioning of the AC filter/AC AirBoxCover

Another video , just mirror the image if you are in the US

Never seen that much water into a MB, but it happens
Hopefully, you get the point. Summary: do not leave your car exposed to the elements for long periods.

hyperion667

Talk to a priest, maybe a roman catholic priest

Senecat

Agreed. I do believe an Exorcism is in order here.

S-Prihadi

BenzV12

I have heard of weak batteries causing weird problems but this one was beyond my imagination as well . You're on the right path hopefully you will get it sorted out .
May the force be with you

S-Prihadi

Usually low voltage will cause "No Com" or as if module is OFF.

OP unique condition is like a module receiveing weird instruction. I guess the water bridges a few modules at the CAN BUS junction bar/distributor, so some modules
get multiple command from other modules and born are new weird commands.... LOL

VBaboli

Here's some update, yesterday I spent many hours draining the water and drying the passenger side front and rear floor. Took the car our for a spin and also to replace the battery, all seems to be fine, no strange behavior, no sign of no exorcism is needed. I am leaving the floor covering up for a few days until the foam completely dries up. However, somewhere in the process, I managed to cut off the sound out of COMAND device, no sound out of radio, blu-tooth, GPS, nothing...
I traced back what I did and all connections seems to be in place. What could I have done to cut the sound??
Many thanks to everyone who helped me finding the issue.

VBaboli

Noted, thanks and checked the fusebox and looks very clean and dry. I am buying a cover since I will leave the car here for extended period of time.

juanmor40

Glad to hear you are making progress, and you are nearly out of the woods.

Did you check the wiring under the front passenger footwell, it is behind the carpet, metal shield. See this video for what I am referring to (ignore the filter change) There is a ground point there as well.

VBaboli

Yes, that was how I was able to see puddle of water and all the electrical junction under water. I had to remove a plastic plug to drain the water. There is a blue connector and I just noticed one wire has broken off. Not easy to put it back. If I know for sure that is the sound wire, I will probably cut them all off and solder to the other side and seal it with shrink wrap.

passenger side under the carpet
In the picture, you see the blue connector and the orange wire disconnected. I need a wiring diagram now

CONFIRMED: The broken wire *is* the sound juice. I don't think can buy that connector, I am thinking to eliminate it altogether and patch the wires together.

S-Prihadi

You have to find the leak source, otherwise it could be a repeat.
Other than potential leak source/s Utube shows from window windscreen or sunroof, also check HVAC water condensation hoses. 2 outlets/hose which pops out of the car above the tranny to drip out of the car.
If that hose somehow loose and came off from HVAC plastic casing, it can be a water source into cabin.


Above is a rear view if we see HVAC complete housing from engine bay into interior

VBaboli

I am sure there is a reason these plugs are there, but if they weren't, the water would've just drained.
Should I not put them back?

took the plug pointing by black arrow out of the hole pointing by red arrow. There are two I had to take out to drain the water.

juanmor40

Better put them back, you do not want an open floor ready from water intrusion while driving.

S-Prihadi

Those holes are needed during manufacturing.
You have to keep them plugged for water protection during rain from road splash etc etc as explained by J40