# 2009 VW CC (MK6) Rear Passenger Door Lock and Power Window Issue



## ckrohn83 (Aug 18, 2014)

Hi all,
I have a 2009 VW CC (MK6) and recently the passenger rear door is making issues. At first the power window wouldn't work (door didn't lock either). This wasn't too bad at first but then battery died over night. Now I do have the RCD330plus radio head unit installed and know there is a drain issue. However, I have installed it 1 year ago and never had any issues. Battery is also 1 year old. I assume at this point, that the car thinks the door is still open/unlatched and therefore doesn't put the car to sleep resulting in the head unit pulling power over night. I have removed the fuse for now and there is not enough drain over night to deplete the battery. But - the door needs fixed:


*Here are the symptoms:*

*Rear Passenger Door*
- Power Window does not work (neither by pushing switch on door nor through driver door switch)
- Door Lock does not work (neither manual nor through remote nor through driver door)
- When door open, it won't show as ajar on the front display (all others do)
- When I lock the car through remote the horn will not sound, the door will not lock
- *HOWEVER,* when I unplug the wiring harness that leads from the car to the door and plug it back in (while car is running), the door lock works manually (pushing button on the door but not through remote) and the power window works as well (only through switch on passenger door - not from driver door switch)
- this is reset when I turn the car off and back on

*What I have done so far:*
- Checked all fuses (due to the battery drain) in engine compartment as well as at the side of the driver dash - all are intact
- I disconnected the rubber boot and wiring harness where door attaches to car and checked the cables. They all look great
- I checked the latch for any dirt and its fine visibly (Have not taken it apart)
- I have not taken the door panel off to look behind
- There are no lights or error codes (OBD2) - don't have any other scanners

*Through research here in the forum, could these be possible causes?*
- Door switch bad or not contacting properly. I saw that the door switch or door latch assembly is a common issue but would this affect the power window as well?
- Wiring defect/broken somewhere? It's weird as the power window and lock do work manually when I unplug and plug in the wiring harness at the door. So the wires deliver the power and the motors for each are working

I am leaning towards replacing the latch mechanism and hope that will fix it.
Thanks for your help!


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## Westlotorn (Feb 7, 2021)

I have the exact issue on my 2010 VW CC with the TSI engine. Pass door windows and locks not working, battery drain issue, battery lasts overnight but any longer it will not start. Did you find a solution to this problem? I am leaning towards removing the door lock actuator or door module.


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## ChefroA6 (Dec 3, 2020)

Do you have access to VAG-Com/VCDS?
Before anything else, you should first scan the Central Locking Module/Controller and see if you have any stored trouble code (such as 00931)


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## Westlotorn (Feb 7, 2021)

I have a Launch X431V+ scan tool, it does read and communicate 2 way with the VW. It says the computer can't see the rear door module at this time. The dash shows the door open 100% of the time. I am now leaning towards the wire harness in the front door opening may be partially broken, I hope to pull that and inspect tomorrow. Thanks


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## ChefroA6 (Dec 3, 2020)

Hmmmm...wouldn't that show your front door open as well?

I would say, if you haven't done any B-Pillar and front/rear door sill trim removal where you could somehow in a freakish way mess up with power/comm wires (to suspect a wiring issue), then I would say that the rear locking module itself is the culprit. Of course, for peace of mind you should check the wiring.
I would think at something else, too. You said that if you disconnect the harness and reconnect it when car is running, then you can lock the door manually (pushing the knob on the door jamb down). In that situation, does the front display still shows the door ajar/open?


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## Westlotorn (Feb 7, 2021)

No time to check the car today unfortunately. I have seen a video and read that the wires that control the rear door come through from the body to the Front Door and from there supply power to the rear door. It said, if you have no window control, no door lock control and your Scan tool shows no communications with the module this is the likely culprit. I fit all the above so I will verify there first although your thoughts on the lock latch may be exactly right also.


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## Westlotorn (Feb 7, 2021)

PS: Front door does work perfectly so far.


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## ChefroA6 (Dec 3, 2020)

The wires probably split on or at the bottom (or in that area) of the A-pillar and head toward the rear door up the B-pillar. I don't have a diagram or could precisely say how the loom exactly splits.
However, unless you have a constant influx of rear passengers that slam the door several times/day, I doubt the wires could get that much wear for that rear passenger door to have a "wire" issue.
For the front: if it works perfectly, then surely you don't have a wire issue, unless somehow after the wires split to go to the rear door you have those particular wires corroded and broken or something of that nature. Even if let's say they got corroded by a leaking sunroof (if you even have sunroof on that CC), why would only the wires for the rear door would have the damage?
I'm trying to think at all of the angles.
As I said, do you still have the "door ajar" symbol for your REAR door on the dashboard display when you're able to lock it manually with the door jamb locking pin? (after disconnecting/resetting the power loom)

(all my comments are based on the OP original post - since you say you have the exact same issue)


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## Westlotorn (Feb 7, 2021)

Update today, Wednesday 2-10-21, played with the wires, pulled the cover off both front and rear door wire harness where it plugs into the body. No obvious damage at all. Can only see a little ways into the harness, need to pull the doors apart to really see the harness. After doing this my issues changed a little.
Now, the door lock is working inside the car at the rear door but not at the driver door or outside with the remotes.
The window has now rolled up, from the inside pass door control only. Driver control still does not work.
The window in the rear pass door formerly dead now drops when you grab the outside door latch, drops about 1/2", let go of the latch and it rolls back up. As it should I believe.
Sometimes, the pass door window will roll up and down from the inside pass door switch now. Sometimes the window motor operates normally from the pass inside door control now. Sometimes it is dead.
New, the dash used to show the pass door open all the time, now it shows it closed all the time, open or closed it shows closed.
So the issues have changed but all still in the pass rear door. My next step I think is to pull the pass rear door apart now and inspect.
No idea why the door locks and windows are acting up at the same time. 
Door module still shows as not connected when I check with my scan tool but I have partial operation.
Still have the battery drain issue and it is a pretty large drain.
One extra, once or twice the door locked and unlocked with the remote, once or twice out of maybe 20 tries.
Trying to get this corrected before tearing into the engine for Timing and Tensioner replacement, parts should be here any day. ECS Tuning.


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## Westlotorn (Feb 7, 2021)

One more item, one time when locking the doors with the remote the horn chirped, only once out of maybe 20 or more tries. Horn chirp indicates all the doors communicated and are locked?
I have a loose connection somewhere, maybe that door lock actuator but I don't think it affects the window operation?


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## ChefroA6 (Dec 3, 2020)

If I had your problem and there's not any matter of security concern (codes or radio code to worry about), then I would definitely just say try to reset the ECU and all the trouble codes that might be stored by unhooking the battery cables and touching them together for about 10-15 seconds. 
If you do so., then remember to do a throttle body adaptation (TBA) after you reconnect the battery 
(Switch ignition on but don't start the car and let the throttle body do its own thing until you can't hear any more clicking noises).
Try after that the functions of both unlocking system and windows roll up/down.
Let's see what an ECU resetting does for you.
The issues don't just aleatorily move from one door to the other b/c you simply wiggle stuff around. I wonder if the Convenience Module itself is shot.


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## Westlotorn (Feb 7, 2021)

Thanks, I appreciate the feedback, the battery has been disconnected every night due to the drain issue. My scan tool offers 2 way communication and I have cleared all codes a few times. I pulled the pass rear door apart today. Wow, not a job for sissies. The entire door has to be taken apart to remove the lock actuator. That is done, now I am waiting to get new parts. Interesting, now that the door is stripped and everything unplugged the battery drain seems to be stopped. Since the door lock has zero tie to the window regulators that I have found I don't see this as the problem but maybe, at least I can hope. It is obvious that something is not communicating correctly. I will post what I find.


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## ChefroA6 (Dec 3, 2020)

I remember pulling apart the rear doors of the long gone C4 Audi A6 to properly replace window regulators.
I'm really curious what comes out of this fix. Sorry for your troubles.


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## Westlotorn (Feb 7, 2021)

Chefro, I see the A6 in your forum name, my son has an S6, modified turbos and controls, making somewhere north of 800 HP, ran the 1/4 mile in around 10 seconds at 134 with no time to special tune. Unfortunately he burned a piston and is fixing it now. It was incredibly fast but that is not something you do to a car you need to run every day for work and travel.


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## ChefroA6 (Dec 3, 2020)

I admire his tenacity, as I'm not much of a gear head. 
I like a few "conveniences" but beyond that I don't have a deep wish inside that I should have been born a Formula 1 or Nascar driver or my car would emulate one of those racing bolides. 
You know the saying - if life gives you lemons, then you should squeeze them and make lemonade. My stupid, frugal philosophy is something along the lines of quarter them and preserve them in the freezer for later... 
Beyond good maintenance or a "convenience" aftermarket trinket here and there, I don't really like to throw away hard earned money on impractical and (in most cases) expensive add-ons for short-lived thrills. If one's a real racing driver, then that's a totally different proposition.
That's exactly where we intersect in regard to a daily driver car's purpose. However, he's your son and you should love and support him no matter what  

Let us know what you find after doing all that rear door work, please.


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## Westlotorn (Feb 7, 2021)

My son has 3 kids now and just bought a new home so I bet his go fast cars are a thing of his past. 

OK the VW. Took apart the entire door of the CC, rear passenger door. Replaced the door lock actuator. Put all back together and no joy. Exact same issues. Everything I am reading and testing points to a Door Harness. I need a wire diagram to come up with the CC wire harness. The loss may be in the rear pass door harness but reading says it is most likely in the far more used doors, the driver or pass front door harness. I understand these are common replacements on these cars with 100K miles or more. Harnesses are available around $200 each. Once I come up with a wire diagram I will start chasing the faulty source. Damn. At least everything in the trunk is not fixed and working.

I am thinking the driver door harness has issues. When I pulled the rubber boot connectors on that door and started moving the harness around I was hearing a faint click click from somewhere in the car. I am not buying any more parts till I can dial into the source.

At this point the Scan tool still says no communication with the pass rear door. All communication feeds from the front driver door master module so somewhere between the driver door and my pass rear door this is lost. The fact it can come and go pushes me again to a broken wire in the harness somewhere.


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## ChefroA6 (Dec 3, 2020)

Everything you're saying would be consistent with a intermittent connection. What's intriguing is the non-communication solely with that right (passenger) rear door, unless the harness splits across the car's floor. Although on a second thought there's some direct communication with the master window and locking controls in the driver door.
I have a Passat Haynes manual - although my Passat was a B5.5. I'll try to look up if it has any electrical diagrams.


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## Westlotorn (Feb 7, 2021)

After cutting the battery power or disconnecting the window motor harness the window works normally until I hit the lock button at any of the lock controls and then the window loses power. Remote, Door lock switch or master lock switch on driver door all cause the power to go away on the window motor. I can disconnect the harness for 10 seconds and power is restored.
There are 4 wires going to the window motor. Brown w green stripe, green, gray, brown. When working the brown with green stripe has 12 V. The other 3 have zero volts. After activating a lock button which kills the window motor the brown with green stripe still has 12 V, the other three have between 9.3 and 9.8 V. Very odd. I took apart the window motor and looked at the control board under a magnifier and cleaned the connections. Could not see any problems but with several mini connections on the small board who knows if the window motor control board is the cause. It appears all functions in the door go through that motor connector. Took apart the driver front door and passenger front door, exposed the wires that are prone to flex as the door opens and closes. They all appear good. Nothing like I found in the failed trunk wires where I replaced 6 wires to get the trunk working again. I am thinking of getting a window motor and plugging it in. If that control board is bad it may be the cause.


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## ChefroA6 (Dec 3, 2020)

Actually my manual is a "Chilton" not Haynes, and it is for VW/Audi Passat (1998-05) and A4 (1996-01).
It wouldn't be current for your 2010's wiring. In older VAG cars 'Brown' usually is/was the ground. Beyond that it is hard to guess what is what.
It sounds like you're isolating the trouble to that rear module. Sometimes the "fractures" in the soldering points are at such micro level that would be hard to be detected even with a magnifier glass. Besides, most magnifying glasses I have come across you could buy in a store don't go beyond 2.5x. 
It would be nice if you could try another window motor, but I know that the CCs are very rare cars to find around, let alone in a junkyard or a u-pull-it facility (if you even have one around).


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## Westlotorn (Feb 7, 2021)

I wrote the days update in another thread " Power Door Locks and Power Windows stopped working" I bought a new pass read door window motor module today and installed. Windows now work well from the driver seat or the right rear pass seat. 
At this point I don't have door locks working in that door. Rear Pass door. Codes now are 00931 says it is the right rear lock. Code 01554 says I have an electrical fault at this same right rear lock.
Dash says right rear door is always closed now.
I have taken all 4 doors apart, inspected all wires that are exposed to movement. Have not found any broken or frayed like the 6 I had to fix in the trunk on this car. I need to do a continuity test but I think I need a wire schematic to make sure I am testing the right wires. One must be broken somewhere or the new lock actuator is not good.
So, Progress but no cigar yet.


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## ChefroA6 (Dec 3, 2020)

I came across something :

00931 Rear Right (F223) 003 - Mechanical Failure | VW Vortex - Volkswagen Forum



> Update: Today I cycled the Child Safety lock switch on the right rear door. It most likely has not been turned for years.
> No more fault codes are showing up now.
> Time will tell if this is the fix.


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## Westlotorn (Feb 7, 2021)

Very embarrassed to say, the whole problem appears to have been the bad Window motor module. I kept thinking on what could be wrong, everything works but the door locks. I took that door apart again and the door lock main wire harness was not connected? It is near impossible to reach so I took the entire door apart once more, windows removed, door handle removed and pulled that new door lock actuator out. Looked at it to determine why the wire had disconnected since I knew it was in there when I installed it. The harness would not clip onto the door lock module no matter what I tried. Comparing this to the old door lock module I found the chinese copy module was made a little differently and the harness would not lock in place, it fits, goes fully on but would not lock in place. I think when I first installed it I slipped it fully in place and moved to the next job without checking if the lock engaged. So I installed the old lock actuator back into the door, the harness clipped in and locked as it should on the old module and when assembled everything is working as intended. Door locks work. Windows all work, no more battery drain. The only think is the car does not honk to verify it is locked. That may be controlled in the car computer and set to be off, I have not checked.
As someone advised early, just replace the window motor module and it would be fixed. Yep Yep Yep. That would have been the ticket. The window motor is easy to install, maybe 20 minutes start to finish. The door lock actuator is much harder. Since I was having problems with the door lock and the dash kept saying the door was open when it was not and then later said it was closed when open or not I focused on that door lock actuator. Thanks for the therapy. I went down tonight after dinner and worked a few hours to wrap this project up.


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## ChefroA6 (Dec 3, 2020)

Look on the bright side - you learned the ins and outs of the rear doors.  
It is rewarding in itself when you discover the solution to the problem.
Cheers


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## Westlotorn (Feb 7, 2021)

Today I tried to install a new leather seat bottom on the driver seat, someone had sat in that seat with something sharp and left a 3" cut. New seat bottom is now hear, I have the seat out and 3/4 taken apart. Wow, nothing is easy. I have done several seats on other cars with no real issue, this one is complicated on the CC. Once that is done on to the timing chain and tensioners and a new intake manifold to kill the P2015 code and give it all new fluids. Then it should be a nice car.


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## ChefroA6 (Dec 3, 2020)

Oh, you have that 2.0 TSI 'sweet' engine that could have the plastic chain tensioner break and make your day...
Smart move to replace it. Did you order the holding/locking tool?


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## Westlotorn (Feb 7, 2021)

yep


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## palorenz (Apr 17, 2021)

I want to thank Westlotorn and the rest of you for this post! Exactly the same problems with the same door as I had, fixed with the window motor, # 3C8-959-704-D-VW4. Mine is a 2010 VW CC Sport. Sorry about all of your pain, but it saved me a lot of time, money. There were actually a couple other posts on this same forum I found that described the same issue and pointed to the motor. So, this isn't such a rare problem. Yes, all control for that door does somehow go through the PC card in the motor. Here are the other posts:








2010 CC Right Rear Door Lock/Window issue


My right rear door is no longer locking. It closes fine but the lock does not work and I see the symbol on the dash that the rear right door is open. I am able to drive the car. I checked the fuses and lubricated the door latch but did not help. The inside lock/unlock does not work and the...




www.vwvortex.com












Is there a way to manually close a power window on my...


Long story short, my rear passenger side window will not close totally and I'm not too pressed to drop another paycheck at the local stealership to fix it! Background: I've been having battery issues all week and finally got it swapped out under warranty yesterday. A short time later I noticed...




www.vwvortex.com


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