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Discussion Starter · #1 ·
Anyone heard of this problem ?
Any suggestions ?

The tailgate window solenoid is triggering automatically and releasing the window (not the whole tailgate just the glass, which is hinged seperately).

Sometimes it opens whilst driving.
Never opens itself with the car locked (thankfully).

This is definitely electrical: sometimes you hear the solenoid firing repeatedly.
Other times it's OK for a couple of days.

I've had the tailgate apart and I cannot see anything obvious.
Tried jiggling all the wiring looms that I could get at, but no change.

Was tempted to just disconnect the solenoid for a while, but if I did I don't think I could ever get the trim off again to re-attach the wires because it needs the window opened to remove the retaining screws.

I suspect a fault in the wiring loom, but that's very hard to trace.
Any known weak spots ?

If anyone has a link to a service manual that would be much appreciated.

Cheers.
 

· King of Rear Clunks
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MG67 said:
I had that when I just bought my car, they reprogrammed the computer and my remote. Now it just opens the backdoor not the glass... works for me...
I'd be pissed if that ever got done. One of the best parts of the car is the glass opening separately by remote.
 

· Ik hou van Holland...
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Kaz said:
I'd be pissed if that ever got done. One of the best parts of the car is the glass opening separately by remote.
I rarely use the top part, I always use the whole back... my gym bag is too big for that little window... BUT I must say that the car is an excellent driver and gas mileage is around 22 mpg...:thumbup: L.A. street / fw driving that is...
 

· King of Rear Clunks
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MG67 said:
I rarely use the top part, I always use the whole back... my gym bag is too big for that little window... BUT I must say that the car is an excellent driver and gas mileage is around 22 mpg...:thumbup: L.A. street / fw driving that is...
Weird. Gas mileage is one of the few things I don't like about the car.
 

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paulbaker85 said:
Anyone heard of this problem ?
Any suggestions ?

The tailgate window solenoid is triggering automatically and releasing the window (not the whole tailgate just the glass, which is hinged seperately).

Sometimes it opens whilst driving.
Never opens itself with the car locked (thankfully).

This is definitely electrical: sometimes you hear the solenoid firing repeatedly.
Other times it's OK for a couple of days.

I've had the tailgate apart and I cannot see anything obvious.
Tried jiggling all the wiring looms that I could get at, but no change.

Was tempted to just disconnect the solenoid for a while, but if I did I don't think I could ever get the trim off again to re-attach the wires because it needs the window opened to remove the retaining screws.

I suspect a fault in the wiring loom, but that's very hard to trace.
Any known weak spots ?

If anyone has a link to a service manual that would be much appreciated.

Cheers.
Similar here ....tailgate glass (only) won't open at all. How do i access the the solenoid or whatever it is that is the likely weak spot? Cheers for any suggestions, not the dealer.
 

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An interesting problem, for which I have a few suggestions.

You guys have to recognize though that you may be confusing the problem by confounding two rather different and electrically distinct functions. There is "locking" and "actuating". Locking and unlocking merely disables or enables the control by which you "actuate" the "lock" (or latch might make more sense in this case). Sounds like paulbaker85 has a phantom actuation problem. Literally his window is opening because the "motor" (that's what BMW calls them) is throwing the window latch open. This won't happen (barring some really weird situation) unless the GM (General Module) recognizes the car as "unlocked", recieves a signal to open and actuates the lock . When you push the button on the back window (or the tailgate) it does not directly actuate the latch. Instead it sends a signal (shall we call it a request) all the way up front to the GM and if "unlocked" the GM sends some voltage along a seperate circuit back to a relay that in-turn closes the circuit that sends 12v to the "motor".

The reason this problem doesn't occur when the car is "locked" is because the GM is ignoring the unintended requests to actuate the window. I don't think its possible through reprograming to tell the GM selectively to ignore a request to actuate the rear window. So it's unlikely that reprograming can mitigate this problem by disabling the rear window. I suspect MG67 had the circuit interupted somewhere along it's length.

My guess is that there is a short in the circuit between the pushbutton and connector at the interference supression filter at the top of the window under the roof spoiler. It may even be in the button itself (a weak or broken spring?). Check the ribbon wiring that leads from the pushbutton below the wiper across the bottom and up the left side of the window. Check the transition points were the wire leaves the glass and look for deterioration of the seal along the length of the wire. Dampness? Corosion? Hopefully, you'll find the problem in this area. It is the most likely given that it is exposed in part to the weather.

As for 320de46m47 with a window that does not actuate the problem may be more difficult to locate because we don't know if the GM is getting the request to open nor do we even know if it regards the window as unlocked (unlocking is probably okay though if everything else works). Start with the same check to the wiring and test for continuity when the button is pushed. If everything tests okay I would jump to checking the return circuit at the rear window drive relay. It could be a bad relay or, less likely the motor (solenoid).

Good luck, and do report how you make out.
 

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thats probably the most detailed and expert sounding reply to a problem ive ever had...but how do I access the ribbon wiring if the window wont open, how does one check for continuity (im not an expert), how do I check the return circuit at the rear window drive relay and how do I check (nay find) a bad relay or motor (solenoid)??

Many thanks!!!
 

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Thanks for the compliment, but I'm thinking I should have refrained from writing anything since I really don't have the time to write long detailed descriptions on how to diagnose these problems. But I guess I am a glutton for punishment and today has been a bit of a lazy day so I'll write a little more. Hopefully, someone will come along who has seen more of these than I have and send you guys directly to the problem.

As for the absolute basics like checking continuity get an inexpensive multimeter and learn how to use it. Also, always be sure to isolate the circuit before testing with modern cars because you will be sending a small current through the wire and if it gets back to an electronic component you'll likely fry it. Also, to do any of this sort of testing you're really going to need wiring diagrams. The Bently manual is an absolute requirement for electrical issues.

My last post was directed more to the guy who started the thread with the phantom actuation problem, so let me offer a little more information that may be applicable to both situations discussed. The "signal" that is sent to the GM from the push button is created by completing a circuit to ground. (specifically to the small ground block located on the inside of the right rear wheel well above the battery and behind the interior trim piece). So the likely cause of the unwanted actuation is an unintentional grounding of the wire that runs from the button to the GM. This could be occurring anywhere along its length. If it is occurring in a connector, the switch itself or along the wire ribbon, the short is between the signal wire and the ground wire. It could also be occurring between the signal wire and metal in the body of the car. All the wires from the tailgate exit at the top right corner pass through a little rubber boot and reenter the car near by. Any time you have a situation like this wires can get bent, abraded and a short to ground can occur. If a wire breaks then the circuit can't close and this will prevent the window from operating at all.

I’m concerned that 320de46m47 may already be way over his head on this and I very strongly reiterate my suggestions above. Yet there are a few things he can do without getting into too much trouble. First thing, and this is a long shot, I would check the fuses. Most of the locking mechanism shares fuses so if everything else works its probably not a fuse. However, I think the wagon rear window relay might be fused separately since it isn't on the other cars. (I can check that tomorrow). If it is a fuse I'd be surprised if something else didn't cause the fuse to go. Another long-shot is the relay itself. I'm not sure where it is but I'll bet it's behind the right rear access panel or the adjacent interior trim. Of course, if you find it you're going to have to test it. Finally, if you're up for it you could remove the interior panel at the bottom of the tailgate and have a look see inside. You could test and also try and manually release the lock. It's attached right up against the wiper motor. Once the window is open you can remove the spoiler and check all the wiring along its length. Finally, and I'm not recommending that you even attempt this, (In other words do not try this at home.) but if I were faced with a totally non-functional window I think my first quick and dirty diagnostic test would be to identify the signal wire in the space behind the right rear access panel just ahead of the right rear tailight and jumper it to ground simulating a button-push. If the window actuated I'd know my problem was somewhere in or near the tailgate assy.

Again, buy a manual and some basic test equipment, and good luck
 

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Discussion Starter · #11 ·
tailgate opening saga

Apologies for not posting what the resolution to my problem was.
It was a short in the wiring integrated into the rear glass.
I ended up having to replace the glass.

All-in-all it cost £650 by the time BMW found what was causing the problem.
Frankly, I'd have preferred the not-operating-at-all scenario that you have as I rareley open the glass on it's own.

Anyhow, there is some wiring running through the glass - silly idea if you ask me.
Mine was shorting somewhere.
Sounds likely that yours maybe has an open-circuit somewhere ?

I did consider, as a short term measure, disconencting the solenoid that releases the window latch. I got the panels off the inside of the tailgate without snapping anything (more than the BMW mechanics could manage, BTW) and gained access to all the bits I needed.
This involved, in part, removing some fixings just below the glass that were only accessible with the glass open.

But it then dawned on me that if I disconnected the solenoid I wouldn't be able to get the panels off again to fix it. Which is, I guess, the situation you're in.

So I'm afraid I can't offer any suggestions except to look for physical breaks in the wiring to the glass or even within the glass.
If you do get the glass open, remove the fixings along the top edge of plastic panels below the glass before you close it again !!

Good luck.
 

· Groccery Getter
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paulbaker85 said:
Anyone heard of this problem ?
Any suggestions ?

The tailgate window solenoid is triggering automatically and releasing the window (not the whole tailgate just the glass, which is hinged seperately).

Sometimes it opens whilst driving.
Never opens itself with the car locked (thankfully).
The tailgate window is doing this exact same thing. The tailgate window will open automatically by itself. It does this when the car is parked and locked. :mad: Has anyone else dealt with the same problem? The car is at the dealership as I type this. He cant find anything so far but said he is going to follow the wires. I'm at a total loss plus the wagon is out of warranty.:bawling:

paulbaker85 said:
Apologies for not posting what the resolution to my problem was.
It was a short in the wiring integrated into the rear glass.
I ended up having to replace the glass.

All-in-all it cost ***163;650 by the time BMW found what was causing the problem.
Frankly, I'd have preferred the not-operating-at-all scenario that you have as I rareley open the glass on it's own.

Anyhow, there is some wiring running through the glass - silly idea if you ask me.
Mine was shorting somewhere.
Where exactly was the short on the glass? How did they find it that it was that? I will suggest about changing out the glass.

Thanks
Alex
 

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I had this problem one time last year. I took it to the (germany) dealer and with out asking any questions replaced something. I didn't ask and it only took them about 15 minutes. I never had the problem again. I have to go to the dealer in the morning, so I will ask the master mech. if he has had alot of the same problems and what the fix is.
 

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einfahrt said:
I had this problem one time last year. I took it to the (germany) dealer and with out asking any questions replaced something. I didn't ask and it only took them about 15 minutes. I never had the problem again. I have to go to the dealer in the morning, so I will ask the master mech. if he has had alot of the same problems and what the fix is.
Thanks dude:thumbup: BTW I love your RIMS.:bigpimp:
 

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Hey alex, I will not be going to the dealer later now see that my new car just arrived on the trunk and I want to try and take delievery ASAP. But as soon as I am finished with AutoExchange I will head to Auto Haus Doerr. OH, I have to take my camera. They got a ASC E90 S3 in yesterday. I will post some pics later.

BTW, you don't have any sigs with the supermesh on your car? Just wondering.

I just talked to the master mech her and he said he starts by cleaning the terminals and if that does not fix it he replaces everything. But, it is usually the conections.
 

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Discussion Starter · #16 · (Edited)
Ignore my last posting - the fault started again.
I'm sure you can imagine how angry I was when the dealer tried to tell me that it wasn't related to the first fault, and that they were right to replace the glass - absolute bull.
Frankly it did always sound rather unlikely, but the problem did go away for about 6 weeks.

Second time the car went in to the dealer, I arrived home from work I found it sitting on my drive, valeted etc.
They never charged me.
I took that as confirmation that they'd misdiagnosed 1st time round.

Anyway, the bit you want to know: it was a microswitch, apparently.

I'd encourage your dealer to look at any microswitches in the area first.
DON'T replace the glass.

I'm not a fan of BMW delaerships.
I expect most of you will disagree - but it seems that owning a "quality" car is just a an excuse for the delaers to charge a fortune for providing a service that is no better than anyone elses.

The car is now sold, BTW.

HTH.
 

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dragging this thread back kicking and screaming because the damn window on my touring still doesnt open and there are some very knowledgeable people it seems here. in fact, correction it does open if i spring the relay by connecting the two poles ..so i know the motorised lock is working fine. if i earth the GM terminal associated (ie end of the line for the switch ) nothing happens. so it seems everything works fine and continuity ok...maybe the GM control unit needs a reprog? i know it can be set (car memory options) to make glass open with button on glass OR button under dash. trouble is i dont have the button under the dash so maybe its been progged to function with the non existent button?
 
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