W208 Window Normalisation Fault - New One On Me?

[Steve@Avantgarde]

Hi Everyone,

I am having a real big issue with a facelifted W208 coupe. I cannot get the front windows to normalise.

The car came in with the O/S window stuck down. The window had frozen closed (because of the weather) and the customers persistant trying to put the window down eventually bent the regulator away from the motor teeth and that was the reason for that.

I fitted a new regulator and motor, with no dramas, and went to normalise the window but as soon as it hit the top the window went down 2 inches and stopped.

Connected star, DCM 1, control unit adaptations, denormalise window proceedure carried out, try to normalise via switch, still doing the same.

Checked actual values whilst operating the window and the hall sensor count isnt moving and is way out of spec (stuck at 65595 counts, spec should be -65000-+170).

The thought I had was that maybe I had a dodgy window motor sent through and that the DCM wasn't seeing the hall sensor counts so I got Benz Exeter to send me a new one, replaced that yesterday, tried to normalise through star again, still the window drops.

Disconnected battery and left for an hour to see if that would reset the DCM internally, same fault after doing this.

I then thought of using the left DCM plugged into the right motor, if it normalised the motor I might have a DCM gone down. After swapping over and trying proceedure still the same fault happening. Reconnected DCMs to correct side and now both windows doing it!! Argggg

Checked can lines to make sure high and low were working and there were no comms errors - all ok.

I then lost interest and drove it to my mate who is an indie in Bristol last night as I couldn't see anything I was doing wrong. We were on it until 9pm and He did everything exactly the same as I did, and we then both drew a blank, we had the thing on 4 different star machines to see if it was a software issue in the star not allowing it to denormaise properly.

He seemed to think it could be that the DCM's are still normalised and that the DCM's wont denormalised even though star says that the DCM's are denormalised!! Confused? I am. I cannot get my tiny brain around this one but if anyone has had similar issues I will welcome your insight and knowledge as I am stuck.

If you have got to the bottom of this long thread without getting bored and are still reading I will thank you for your time in advance!

Steve

 

[Alex Crow]

well this is fun! if the hall sensor count does not change then you have an explanation of why it will not normalise, and you have disconnected the battery which would normally do it. the DCM does not really need any external reference to normalise, and is hard wired to the hall sensor in the motor. so have you checked the hall signal at the DCM (with eg a 'scope or meter on acv)? this still does not explain why the N/S will not normalise either though...

what values do you get for door pin switches from the PSE module? could it be that the DCMs think the doors are open? i am guessing the N/S is just playing up now because it has been denormalised, and there is an external issue elsewhere, have you been through all the power supply and earth connections at the DCM too?

 

[Steve@Avantgarde]

Hi Alex

I have been through all the power supply and earth connections and they are ok. CAN high and low is also there. I checked the hall signal with a scope and all is there. Actual values see that the doors are closed!! I dont know where else to go.

I took the car to MB Bath this am to see if our star machines werent allowing to denormalise the DCMs but all was the same using their compact 4 star.

I've given up on it for the weekend and put the customer in my car until I can fix it.

 

[Alex Crow]

how about codings. see what you have in the EIS particularly, but DCMs, PSE, OCP and SAM as well. it is vaguely possible that if for instance EIS has a brain f#rt it might be coded for eg a 202 or 210 (ie 4 door) or something stupid like that.

 

[Steve@Avantgarde]

I checked the EIS DCM is coded and recognised not unless I missed something. There is nothing in OCP PSE or SAM for sure as I went through those with 4 different star machines and then rechecked by Steve at BG Griffiths. I am honestly stumped!!

 

[Alex Crow]

steve, there is something wrong with it. let us know when you get it sussed

 

[Steve@Avantgarde]

Will do. I cant wait to sus it cos its doing my head in.

 

[Howard]

Without wanting to teach you guys to suck eggs , have you tried just resyncing the windows using the buttons ?

Open them , then put them all the way back up ( holding the switch down , not using the one touch mode ) and then holding them in place for a couple of seconds once it's up ?

Worked on mine when i replaced my battery and had to resync the windows ( which did exactly as you describe , all the way up and then dropped two inches ) ..

Apologies if this was the first thing you tried :Oops:

Good luck.

 

[Alex Crow]

yes, this is what steve means by 'normalising' the windows, and is not normally a difficult thing to do obviously!

 

[Howard]

Sorry :Oops:

 

[television]

Do not forget that if the glass is too tight in the tracks it will think that there is an obstruction and drop 2"

The door controller could be contaminated on the memory side,, there is a mod or replacement for this

 

[Steve@Avantgarde]

Malc

Already checked and adjusted the window to the loosest possible. Whatever I try the windows drop by 2 inches when reaching the top or if finger is taken off the switch whilst going up.

Havent heard of your mod you talk about is this on a TIPS document? If so could you PM me as any help would be greatly recieved.

 

[television]

It is the ECU that loses count on these faults and a new ECU was brought out,,I will try and find details but they are in WIS

 

[Alex Crow]

going back to basics, and i am sure you HAVE done this, and howard has touched upon it - have you normalised at the bottom of travel as well as the top? obvious i know, but the w208 needs it doing for both top and bottom stops if i remember correctly.

what does the LCP show for window switches, all 5x positions for each switch OK.

 

[Steve@Avantgarde]

I have tried the lower position stop. The issue is lying in the fact the DCM's arent seeing the hall sensors move so then cant work out a top and bottom stop even though a scope is saying the hall sensors are working.

In LCP I dont recall seeing a function for window switches. I will have to recheck this.

 

[Alex Crow]

The issue is lying in the fact the DCM's arent seeing the hall sensors move so then cant work out a top and bottom stop....

certainly sounds like it steve.

if it helps you are not the only one, we all have these weeks when every problem seems to be a new one...

 

[geezer255]

going back to basics, and i am sure you HAVE done this, and howard has touched upon it - have you normalised at the bottom of travel as well as the top? obvious i know, but the w208 needs it doing for both top and bottom stops if i remember correctly.

what does the LCP show for window switches, all 5x positions for each switch OK.

After I called you the other week about the flat battery I had 20mins of this before it suddenly started working as it should do

 

[television]

On WIS there is the fault "window drops down after fitting new ECU" on AF54 . 21-P-6000A and this tells you to go to AR72.29-P-1000K apparently the wrong ECU

 

[Alex Crow]

he only changed the motor malc, the DCMs remain, and a new fault with the N/S too that was OK before!?! feeling sorry for you here steve, but we all get them...

 

[television]

he only changed the motor malc, the DCMs remain, and a new fault with the N/S too that was OK before!?! feeling sorry for you here steve, but we all get them...

But this still leaves the ECU as tho only thing left, we have had some similar faults where the ECU gets contaminated electronically