Rear door not always unlocking - Diagnosing issue

[chinnyhill10]

Hi,

The rear passenger door (drivers side) wouldn't unlock today on my 08 A3 with the keyfob, but was fine if opened from the inside.

I've had a look around on the web and see its a common problem. However the symptoms listed on here and other forums don't quite match what I am experiencing.

I tried the various techniques listed but none seemed to work. So I started to have a fiddle with a screwdriver in the latch and noticed the mechanism seemed a tad sticky. So I added some grease and WD40 and it eased up.

After this it seemed to work better but its still erratic. Sometimes it opens, sometimes it doesn't. If you try to open the door while it is locked I can guarantee if you unlock the car it will refuse to unlock if you then click the keyfob.

When it does unlock you hear a satisfying click as opposed to a weaker click if it does not unlock.

So is the mechanism still sticking due to poor lubrication, is it a dodgy motor or is it the dreaded cable problem inside the door?

The reason I ask is because if it is a motor or relay in the central locking system, my car warranty covers it. Any other issue and they'll sting me. So I want to diagnose this myself without causing any further damage just in case I can get this repaired for free.

Cheers.

 

[mike foster]

It is likely to be a sticky, gunged up operating system for the microswitch inside the window winder motor.

I had exactly the same problem on my 2006 sportback two months ago and thought it might be the door module which is part of the motor and you can't buy just the module. Eventually I took the whole thing apart (which is very complicated) and cleaned and re-lubricated everything.

Six hours later it was back and working ok and still is !

The basic problem is inside the motor and therefore any dealer will just replace it. Chances are they have never even seen inside the casing.

Unless you feel particularly confident with removing the door panel, disassembling the motor and then trying to get all the bits back together (hence the 6 hours) and then re-setting with VCDS I strongly suggest you leave well alone !

They will just replace the unit and throw the other away !

 

[chinnyhill10]

It is likely to be a sticky, gunged up operating system for the microswitch inside the window winder motor.

Thanks. That could be good news. The motor and relay are specifically listed as being covered.

I'm always wary with these things as warranties always try to wriggle out of stuff. On my last car (a Golf mk5) it had an alarm sensor fault that wasn't covered by the VW warranty. I was furious!

Cheers.

 

[Cossie_boy]

I think mines doing this too!

 

[Ash187]

i have this on the passenger side... its not that much of a problem but now that i see its not just me i will look into the issue and see if i can clean it out soon when i get some more time

 

[Helifella]

Interesting read - my parents VW Touran does exactly this. Will forward. Cheers