# rear door won't unlock



## tortoiseandhare (Apr 8, 2010)

Just recently, a couple days ago, when I unlocked all my doors, I couldn't open the right rear door - it was still locked despite repeated attempts with both the fob and the lock/unlock button on the driver's door. Also, when all doors are unlocked, the lock light on the unlock/lock button of this right rear door remains illuminated. It cannot be opened from either the outside or the inside. Pressing the lock/unlock button on this door does nothing.

Any suggestions?

~Loren


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## n968412L (Apr 23, 2009)

tortoiseandhare said:


> Just recently, a couple days ago, when I unlocked all my doors, I couldn't open the right rear door - it was still locked despite repeated attempts with both the fob and the lock/unlock button on the driver's door. Also, when all doors are unlocked, the lock light on the unlock/lock button of this right rear door remains illuminated. It cannot be opened from either the outside or the inside. Pressing the lock/unlock button on this door does nothing.
> 
> Any suggestions?
> 
> ~Loren


I had this on my V10 about 18 months ago. It was the rear left door in my case. Then miraculously a day later it just started working again... 

So I'm no help to you in diagnosing the problem.

Good luck.

M


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## PanEuropean (Nov 3, 2001)

Hi Loren:

Hopefully, it will be one of those strange problems that goes away after a day. In the meantime, try activating and deactivating the child lock control (on the driver door) to see if that makes any difference.

You could also try physically exercising the problem lock by mechanically unlocking and relocking it, maybe that might wake it up and make it function again - see this post for more info: Door Locks - how to manually lock the doors if no battery power is present

If none of those activities fix the problem, you will need to do a diagnostic scan to see if there is a problem with the controller for that door - it is a slave of controller 46.

Michael


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## tortoiseandhare (Apr 8, 2010)

Michael,

Thanks for the suggestions. I tried exercising the child lock buttons - works great on the driver's side rear door, but has no effect to the passenger rear door as far as being able to open it. I don't think the link you provided about mechanically locking/unlocking doors is going to help me, as the door is shut now and cannot be opened from either side - so can't get at the plug within that door jamb.

This may or may not be related - my trunk lid has now decided to unlatch by itself, either after a short drive, after closing a door, or after just sitting awhile. It's not the automatically opening trunk - I have to lift it open. When I close it now, I hear the locking mechanism as usual, but it either doesn't actually lock at all, or if it does it unlocks shortly thereafter, illuminating the open trunk light on the dash. Yikes...

I will get my little laptop charged up and plug in to see what I can find there.

~Loren


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## insighter (Jan 10, 2012)

I also had such problem. unlock function sometimes didn't work. Sometimes worked.
There is a part(module) connected to the (un)lock button. I replaced the part and then it is normal until now.
Hope this helps.


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## Paximus (Aug 26, 2011)

Hi Loren,

I have searched through the wiring diagrams, but I cannot find a common-mode problem area between the left rear door controller and the trunk lid controller (via the Convenience Controller) which would not also affect the other three doors. They all share the same CAN-bus attachments, so if one controller was dragged down then they all would be down.

In which case, the problems are unconnected, and the most likely place to look for the trunk lid issue is in the cable loom between the tube that carries the wires into the trunk lid and the cassette that manages the slack as the lid opens. This is a known point of failure, where the insulation is shredded and adjacent wires touch intermittently. This causes random effects involving the rear lights and trunk lid, potentially including unwanted operation of the lock motor.

As for the door, I would do a diagnostics scan to see what it thinks is going on. In the last resort, powering down the door controller by removing fuse SB3 (15A, in the panel by the driver's knees) for 30 seconds then replacing it might reset the controller and give temporary control of the door lock. This will also power down a front door. Some re-adaptation of the windows might be called for afterwards, by simply running them up and down as if to go past the end-stops.

Chris


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## insighter (Jan 10, 2012)

To make my reply clear:
The same problem I had is about rear window unlock button not trunk.


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## tortoiseandhare (Apr 8, 2010)

Just an update on my Phaeton phantom problems... 

I took the car in for its 130,000 mile service, which was just about due anyway. The trunk latching problem is due to a faulty latch mechanism, and they're waiting for price/availability on that. Maybe it just needs some WD40? The right rear door they have been unable to open. I asked if they had shut the power off and they responded that they had - but I passed along the info about fuse SB3 and they will try that when they return to the shop on Monday. Their other plan is to attempt to remove the door panel, something that is normally done with the door open, to get at the locking mechanism and manually disengage it!


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## Gabs08PHTN (Jan 6, 2011)

tortoiseandhare said:


> Their other plan is to attempt to remove the door panel, something that is normally done with the door open, to get at the locking mechanism and manually disengage it!


Hi,
If you remove the door panel you do not access the locking mechanism, as there is an aluminium panel behind the door card. 
In any case in order to remove the rear door panel you have to do it with an open door, since there is a bolt that needs undoing behind the red led lamp that sits on the edge of the door plus another one located at the bottom of the door.
If they were to remove the wooden trim, then they would access the bowden cable than runs towards the locking mechanism and the lock swich. Perhaps they want to bypass the switch just in case it is the faulty part...

Gabriel


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## tortoiseandhare (Apr 8, 2010)

Just got a call from VW service - they have successfully removed the door panel, at least far enough to see, but still cannot actuate the latch. They now suggest they need to drill a 2 or 3 inch hole through a plate to access the latch, which they say has jammed. Besides the 2 or 3 hours labor already into it, the estimate is now another $1500 for additional labor and new latch, and maybe a new part to replace whatever will get the hole in it. Aaackk!  I told them to hold off - I want to take a look at what they're doing - will see if I can get some pictures...


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## tortoiseandhare (Apr 8, 2010)

The techs have been unable to open the door, either mechanically or electronically. The fuse procedure has been tried, as well as issuing commands via VCDS to unlock the door. Other doors will unlock, an error message is returned when attempting to unlock right rear door.

They have successfully removed the door panel, but as mentioned earlier in this thread, that does not reveal the latch mechanism. They suggest cutting a larger access hole in the window regulator to gain access to the latch, which they say is enclosed in a white plastic shroud. This will have to be cut away, and even then they're not sure they will be able to unjam the latch and open the door.

Bottom line is I can choose to have them put the door panel back on and have a 3 door Phaeton, or continue digging, which will probably cost upwards of $2000 with labor, new latch mechanism and very possibly a new window regulator. Right now I'm leaning towards a 3 door Phaeton unless anyone has a clever idea that may not have been tried yet. I'm not sure how to post photos, as it appears that I can't upload from my computer. I'm posting a couple URLs - if photos appear, the one with the red marking shows where they would cut if I give the okay.


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## Gabs08PHTN (Jan 6, 2011)

Cannot you purchase a rear door from a written off Phaeton in order to install all the working and usable bits and pieces of your curent rear door? Perhaps that way, even the current door is needs to be badly damaged in order to have it opened, the bill will be lower.

Gabriel


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## tortoiseandhare (Apr 8, 2010)

A parts door is a possibility - I may have located one, although the price on the door is $750...


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## cbh123 (Aug 25, 2013)

If it were me, I would be digging pretty deeply into the other rear door, and figuring out how exactly the teensiest details of the lock/latch mechanism works. Armed with enough knowledge, I am 100% certain that the door is openable without damage. 
If you are somehow not capable of doing this... Remember the car was built by assembly line people with electric screwdrivers.... I suggest that you go to your city's high end car audio shop, the one that would do exotic cars, and challenge the to get it open. Those guys are very expert at disassembling cars.


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## PowerDubs (Jul 22, 2001)

Pulling the interior silver handle mechanically yanks a cable which should pop the door latch, so that rules out any and all chances of it being electrically related in any way short of the car constantly sending power to the latch to lock non-stop (highly unlikely). That would be resolved by pulling the inner handle while the batteries were unplugged.

What do you feel when you pull the inner handle?



















Cutting a hole won't accomplish anything. I think you may have to live with 3 doors.


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## tortoiseandhare (Apr 8, 2010)

It's at the VW dealer. They feel resistance when they pull the cable, but no movement at the mechanical latch. Same with the outer door handle. Ordering an unlock via the computer just gets an error message back for that one door.


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## PowerDubs (Jul 22, 2001)

Honestly? I would try pulling quite firmly on the inner handle while putting myself into the door and having someone pull the outer handle at the same time. 

I would just be somewhat gentle on the outside handle...putting the brute force into the inner panel as you try to wham it open. The inner handle and door panel are easy to find use and easy to replace if marred.


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## tortoiseandhare (Apr 8, 2010)

I'm going with the 3 door Phaeton for the time being - had them put the door panel and trim back on. We don't use the back seat frequently enough to warrant the expense and the risk that they couldn't get it open even if they did cut through to get to the latch. Maybe if I find a rough road it'll unjam on its own some day...


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