W202 Front electric windows ... arrgggggggg

[ozzy_c180]

Please help,

I have a strange problem with my front electric windows and electric mirrors. They have stopped working, back windows work fine. However, when i disconnect the battery then reconnect things are fine. Recentley the key stopped locking the car to. But whenever the battery is disconnected things are fine... Please Advise

Any help appreciated!

 

[bigasotonuk]

Hi,
Ok the windows work when you reconnect the car battery, when do they fail? does it correspond to using any other equipment? When they fail do your door mirrors, central locking, puddle lights (if fitted) still work?

 

[ozzy_c180]

Hi

Central locking works from the inside but not with the key. Windows just stop working after a couple of days or a week. I cant think of anything that would cause it. I can remember once i got a new key the alarm went of and i couldnt turn it of so i disconnected the battery after that day this problem started.

Thanks

 

[ozzy_c180]

Hi

Central locking works from the inside but not with the key. Windows just stop working after a couple of days or a week. I cant think of anything that would cause it. I can remember once i got a new key the alarm went of and i couldnt turn it of so i disconnected the battery after that day this problem started.

Thanks

 

[television]

This sounds like a CAN fault and water,,see if I can find anything

 

[bigasotonuk]

Hi,
I thought that too Malcolm, but both front doors to fail at the same time i thought unlikely, I was thinking the comfort control unit in the boot somewhere, on a pre-face lift models it is mounted adjacent the battery.

 

[television]

I think the modules are in the rear doors and water getter in there is modified modules or one makes the existing waterproof

 

[harri875]

electric windows

Hi Television, ive got exactly the same problem as Ozzy and its doing my nut.I see by the amount of posts that its a common fault so you would think some of the ex Merc mechanics would have some idea how to fix it.The controllers obviously work as they reset after the battery is disconnected and re-connected so i cant see the point in testing them. Is there a main controller and if so how do you identify it? thought i might have a look at and see if there is any sign of water.

 

[television]

Hello Mr Harri and welcome to the forum.

As far as I see it and what the MB service sheets say the problem is that water gets into the door controllers fitted into the rear doors,,these things are CAN BUS connected and talk to each other,,though the fault my only be on one side both sides can be disrupted.

Either replace both with the modified controllers or dry them out and make them water proof baring in mind that if water did get in, it must be able to get out

 

[harri875]

electric windows

Thanks for that Malcolm i will remove the door cards and have a look at the controllers,by the way can you explain CAN BUS?

 

[dragon]

Also check the battery is fully charged.

 

[television]

Can Bus is a two way data check system that can do 2 checks at the same time, one high speed and the other at low speeds,, the important things like safety and engine management use the fast check, and the remainder the low speed.

These checks tell the main computer the state of all of the electronics in the car. when some modules get water in them the CAN signals get mixed up with other things or not recognized so that the car does not know that it has these things on the car,, in this case the car does not know that it has the comfort feature,, so they will not work,, windows that is.

I could go on for pages of it, but the above is a rough outline