Rear doors fail to lock

Hi, folks. Haven't posted for a while. My problem is:

When I lock the doors (using either the front driver-side interior lock button or the key fob) the front doors lock and the alarm system engages, but the rear doors don't lock, so that if I forget (or the fob unlock button button doesn't work, which is a more-frequent-than-not occurrence now--also a problem, but not as bad), I can open the rear doors, even though the front doors are still locked, and the alarm system goes off, and since the key fob unlock button doesn't work more-often-than-not, I have to manually unlock the doors w/ the key to turn it off--more embarrassing than anything else, but I've gotten tired of it. Is this a bad relay somewhere; did I inadvertently improperly set something w/ my VAG-COM; anyone have experience w/ this and know how to fix it? Also just noticed that unlocking the driver's door manually w/ the key doesn't unlock the passenger door.

Thanks!

Those lock mechanisms are a known failure point. Replacements are cheap and readily available on eBay and AliExpress BUT you need to be sure to order one with the correct connector. Two different styles were used, one with 6 pins and one with 7 (IIRC). Best to send a picture of yours to the seller before buying.

Putting them in is fun. You have to remove the exterior door skin and perform a little dance to get the door handle off. Once you do that it's pretty straightforward.

If both locks are failing, it might be broken wires in the wiring harness in the driver's door hinge.

Thanks, guys. In the actual hinge? Either way, can anyone point me to video(s) of the procedures to take off the external door skin/get at the inside of the hinges? Thanks again!

DLG

First do a visual check of the wires in the accordion boot. I've never done it, but you should be able to detach one end, compress the boot, and look at the wires. The 06 Jettas are notorious for broken wires, sometimes repairable, sometimes requiring a new (longer?) harness.
Good luck

Door latch failures are common.

You can have several failure modes, all fixed with a new latch.

Latch microswitch will not show the door open or closed when it should

Latch will not unlock or lock when it should.

I do probably 30+ of these a year, maybe more. Heck, I've done two on a couple of my own cars so far this year!

The car will have DTCs set for door lock module usually. I've had more than one car that had all four latches bad!

When you say latch, do you mean the actual notched lever in the door that engages the U bolt in the door frame to secure the door closed?

I managed to get the driver's door boot off one side--a *****--and checked all twelve wires by pulling them individually--two were a major *****--and based on that they all seem continuous. However, are you sure I don't need to check the other door boots as well?

Thanks!

The latch is the mechanism in the door that houses the actual lock actuator and all the microswitches. 100 to 1 odds both of yours are bad. VCDS will confirm it with DTCs for "door lock module something or other".

Hey Oilhammer, how much labour is involved in getting someone to replace these? I have a couple bad ones myself.


Thanks!

On the A5 cars, the labor is 1.3hr each, for both the front and rear. These doors, while it may *look* intimidating, are actually one of the easiest cars ever to work on. They come apart fairly easily, and because the skin unbolts from the outside, you are never fighting to get into some tight space for access. The whole thing is wide open. You don't even need to mess with the window regulator.



And the older cars can benefit from the newer style harnesses, too:



The one installed in the car already in the pic is the new style. The one in my hand is the old trouble prone style. Anymore, I never do just a harness or just a latch, I do them both if the car still has the old style harness. Unless the customer absolutely refuses. But given how commonly the latches fail, and how they are only another 5 minutes of work to swap when doing the harness....

oilhammer said:

On the A5 cars, the labor is 1.3hr each, for both the front and rear. These doors, while it may *look* intimidating, are actually one of the easiest cars ever to work on. They come apart fairly easily, and because the skin unbolts from the outside, you are never fighting to get into some tight space for access. The whole thing is wide open. You don't even need to mess with the window regulator.



And the older cars can benefit from the newer style harnesses, too:



The one installed in the car already in the pic is the new style. The one in my hand is the old trouble prone style. Anymore, I never do just a harness or just a latch, I do them both if the car still has the old style harness. Unless the customer absolutely refuses. But given how commonly the latches fail, and how they are only another 5 minutes of work to swap when doing the harness....

Click to expand...

Thank you very much for all the info! That was exactly what I needed.

RV9Factory said:

Those lock mechanisms are a known failure point. Replacements are cheap and readily available on eBay and AliExpress BUT you need to be sure to order one with the correct connector. Two different styles were used, one with 6 pins and one with 7 (IIRC). Best to send a picture of yours to the seller before buying.

Putting them in is fun. You have to remove the exterior door skin and perform a little dance to get the door handle off. Once you do that it's pretty straightforward.

Click to expand...

The term 'fun' is clearly sarcasm. Awhile ago I had to do this and was quite frustrated with the door handle removal procedure, so I made a Youtube video about the door handle mechanism that I thought would be helpful to anyone having to deal with these door handles:

https://www.youtube.com/watch?v=Ih9GpIc7pDY&t=8s

Not many people seem to have watched this, but I have received some nice replies that indicated it was helpful to some.

I think they are super easy.

Now, there are some other cars I could invent new swear words over, but not these, not even close.