balintv

Hello,

I am facing an issue with my front passenger side (right hand side) power window and electric mirror.
It stops operating, but all the others are working fine.

After disconnecting and re-connecting the battery everything goes back to normal, for a few days.
(Therefore I thing this is not related to electrical contact problem of the switch)

What I observed, that this breakdown usually happens when the car is not used for a few days.
In the meantime the car does not react first time for the keyfob remote open, I have to press it twice to open,
after that the window and mirror will not operate.

I have read somewhere that it can be related to the rear side power window motor (with integrated control module),
as it can corrupt the CAN network.
I have disconnected the passenger rear side to see if it makes a difference, but no success
front worked for a while, but now stopped again.

Any help is appreciated.

Thank you !

Russell Ormerod

Did you disconnect both rear motors

Russell Ormerod

You need to measure the CAN voltages to see if they in spec. Most often its caused by a rear door control module it could be either side or even both sides

balintv

Thanks for the hint.
I will disconnect the other side rear motor as well at the weekend.
I am quite curious if this is going to solve the issue....

Anyhow, I plan to check the CAN line with an Oscilloscope, to see what is the exact problem here,
but I will wait to have a bit better weather here, before I peal off door panels...

Russell Ormerod

There is a CAN connector in the LF door sill (rhd car) were you can disconnect each node. With a scope or volt meter you will see activity on only one line.

cwp

There is a small relay behind the battery that controls all windows. That relay going bad could be your problem. Try replacing that.

Russell Ormerod

If this car has extended vehicle networking i.e. CAN modules. There is no relay behind the battery.

Moxostoma

I'm having this problem on my 2000 C230. The driver's window is inoperative. If I disconnect and reconnect the battery, it will work for a day or two then won't work again. If I understand what's being said here, it may be a problem with a window other than the driver's side. Can I just pull the fuses for the other windows to see which one is causing the problem?

Russell Ormerod

Nope, pulling fuses won't help, you need to pull the can bus wires off the network

Moxostoma

And these CAN bus wires are on the motor in each door?

Russell Ormerod

There is a connector in the door sill, but yes you could unplug at the motor

Start with rears

Moxostoma

When I slide the rubber bellows off the wire to the rear door, I see one thick yellow wire but no plug. Is this where I should be able to disconnect the motor without removing the door panel?

khomer2

Pardon my asking but did you try the procedure of resetting that one window? You mentioned that you disconnected the battery. This resets the windows and you may need to reset with the power button on the center console.

Russell Ormerod

Reset will not help an inoperative window, sync is only to learn end stops!
Best you remove the rear door panel, to unplug motor, because I can assure you that will have to remove the panel to fix the problem anyway.

Moxostoma

I've removed door panels and unplugged window motors one at a time on both rear doors and the passenger side door. The driver's side window still stops after a few days. Is there anything else I should check (the sunroof maybe) or is it time to replace the motor on the driver's side window?

cwp

I fixed mine by replacing the master power circuit board located at the gershift. Very easy and simple and part cost under 30 bucks shipped!

Russell Ormerod

Unplug boTh rears and test

Moxostoma

I unplugged them one at a time and left them unplugged as I went along. Should I try plugging some in and see what happens?

hyperchick1

Does it stop working altogether or does it hesitate? How long are you disconnecting the battery for?

If it's hesitating, you need to disconnect the negative side of the battery for 15 min then reconnect it and reset all the windows. Mine were having issues going up. The windows would go down but would not go up. This is the solution the Mercedes tech gave me and it worked.

Moxostoma

It stops working completely.

I took it to a shop. They ran a diagnostics and said I needed to replace the modules in both the driver's and passenger's side and the master switch assembly. I got used parts from ebay. When I went to pick it up everything worked but the passenger's side window was making a noise. They said I would need to replace the motor soon.

I took it home and, after a few days, none of the windows work.

balintv

Hello,

Finally I have managed to find the root-cause, and now I can say my issue is solved:

I the passanger side (Right hand side in my case) footwell there is cable tray below the carpet, which runs below the door.
You can find several connectors in this cable tray, and one of them is to connect the CAN network cables of all control units
into one star-point. (Picture attached)

This connector was so badly corroded (as a result of cracked windsreen seal, water got into the footwell directly into the cable tray),
that it avoided my door-control module to communicate on CAN properly.

After replacing the connector everything works fine for several months now.

Moxostoma

Balintv: I'd like to try this. How did you get to this cable tray?

Never mind. I found the procedure here: https://mbworld.org/forums/c-class-w...nt-carpet.html

Moxostoma

Well, Balintv's fix didn't work for me. Time to take the car back to the shop and see if they can figure it out this time.

Before that, though, I'd like to try one more thing. I theorize that the problem is caused by the system that opens all the windows and sunroof when the remote is held down when unlocking the doors, or, when the doors are locked, closing them all. Is there a way to bypass this "feature" but still have the interior switches operate the windows - pull a fuse maybe?