I have seen several threads about the vacuum locking system going bonkers but this is different. The rear drivers door is locked and I can't unlock it. I can't even pull the panel off to get inside because it's locked and I can't open the door. Has anyone come across this issue? All the other locks work fine.

 

Ok this is weird. I have had this issue for about 4 days. In just a stupid attempt to see what would happen I sprayed WD-40 right on the lock button. Couple minutes later it unlocked like nothing happened...

I went ahead and pulled the panel and am going to lube everything with a real lithium grease spray...

 

You sprayed WD-40 on what lock button?

 

Check the vacuum hoses to determine if there is a leak due to a cracked or broken hose.

Due to the age of these vehicles, it is common for the central locking system to malfunction due to a vacuum leak.

 

Dumb question here Ospyguy, but you do know about the child locks on the back door don't you? If that gets set you can only open it from the outside of the car.

 

Child locks weren't on. It was just staying in the locked position. I sprayed the actual lock indicator that sticks out of the top of the door panel. My thought is there was some kind of vacuum imbalance and the spray released that when it got to mechanism.

 

Whatever it was, you should pull that latch mechanism out and clean it up good and lubricate it. I drive my Audi's over 200,000 miles and every now and then I have to do that.