W202 Electric windows

[4fold]

Hello, Could I get some advice please. I have a 98 C180 auto elegance. If I leave the car for any period over 20 hours without driving it one or both electric front windows will not work along with the associated electric mirror. Its usually the left one but the right will act up first at times. The solution for me is to disconnect battery earth for 1 min or remove fuse 7 in the front for the left one or fuse 3 in the boot for the right one. This does not always work but the battery method always does. Sometimes the remote unlocking system only works up close and at times the front interior courtesy light will not work. All these can be cured temporarily by the aforementioned battery disconnection. I posted this problem before and members were kind enough to help, suggesting comfort unit 5. I havent been able to find this. Any help advice greatly appreciated.

 

[Dec]

Is your fuse lay out the same as mine, if it is, try removing fuse 7 in boot for rear window lifters to see what happens over the next few days.

According to Haynes Manual (number 3511), from August 1996 onwards the comfort unit is either behind the instrument panel or behind the drivers door card near the hinges and not to be mistaken for the airbag.

Try the fuse first.

Dec

 

[television]

As from 06-06-97 the module is at the top front of the door.

If you need any door cover removal instructions please ask

 

[4fold]

Thanks for your prompt replies. It looks like both modules in the doors are acting up. Would I be correct in assuming that the window system goes into hibernation after a certain period of standby. Is it possible to repair these units, or if replacement is required do they need programming to the car. What governs this dormant state if it exists. Thanks again.

 

[4fold]

Hi Dec,
I just had a look at your attachment and front and rear layouts are totally different to mine. I'll identify the rear window fuses and try your suggestion. What part of Ireland are you in? Thanks again.

 

[television]

I have sent you via Email the list where all the things are

 

[4fold]

Thank you Malcolm. Unfortunately it looks like that procedure is for an older model. I do not have N57 and K24 units in the boot area therefore I assume the control modules are in the doors. Before I remove these I wonder is there another control unit such as central convenience locking that sends a wake up signal to these units after a period of non-use. Thanks again.

 

[television]

That paper covered the first from 95 and up , there are no others in between. If you do not have all of the parts,then your car does not have all of those features

 

[roofless]

i wonder if a low battery could cause this fault as it seems to only be if it's not used for a time

 

[4fold]

You are correct Malcolm, my car doesn't have a sunroof only 4x electric windows with control units in front doors. Thanks again

 

[4fold]

i wonder if a low battery could cause this fault as it seems to only be if it's not used for a time

Thanks Roofless, I haven't checked the voltage for a while, but the battery is relatively new 8/9 months and changing it made no difference as this problem has been going on for years.

 

[Dec]

Regarding removing the fused, someone had a similar problem in that the rear motor wiring got wet and caused all sorts of problems like yours, the disconnection of the rear passenger side window motor seemed to clear up the problem and he was trying to dry out the motor, so that’s why I was thinking that disconnecting the rear motors might show something up.

Dec

 

[television]

We also had the other post where the guy solved the problem by disconnecting the all time live memory feed to the ECU and joining direct to the plus on the ECU.

The modules in the door can get water in them, on the CLK the modules loose count of the motor turns, and re programming on STAR can hel for a time

 

[4fold]

Thanks for replies. I've checked door modules some time ago for moisture and both were dry. I also tried disconnecting rh rear window motor with no success. My worry is if I replace door modules and it turns out to be some other module upstream of these. Maybe I'm just being too mean or paranoid. Thanks again.

 

[television]

I will do a further search, for anything

 

[4fold]

I was looking at some other posts and they mention the car going to sleep. Could someone explain this as i think that might be my problem. I think that my car goes to sleep and on been woken does not activate the window control modules. Any ideas anyone. Thanks again.

 

[television]

There is no go to sleep on a 202, this did not start until around 2001, and new cars brought out after that date

 

[television]

I have found another thing and this has worked before.

The fault is in the rear doors, and I have sent you the paper, intersting that it also includes the wiper

 

[4fold]

Many thanks Malcolm, I'll check this out soonest and get back with results in a few days. Thanks again

 

[4fold]

Just an update on window/mirror problem. Malcolm you were correct in diagnosing a CAN problem. It would appear that the right hand passenger door unit is causing the problem, when I disconnected and reconnected the problem cured itself. Since Mercedes use a redundant Can bus I cut one of the wires to the unit ( dont know if this is high or low ) in order to force it to be read by the other and so far no further problems i.e. everything working as it should. Thanks again for your help and advice. BTW a new unit is approx £400, nearly more than the car is worth.