I have a 1999 A8 Quattro 4.2T,
A problem suddenly happened the other day. All door locks seems to not work any more... I press the lock button on master key remote, the car signal lights flashes, a horn will confirm all door are locked, but actually notthing happen. I have to manually lock and unlock with the key everytime. Even my power door switch on the inside not working. Everything has to be manual.
Very confused... Please help!

 

Did you check the fuses?

 

No i have not, but i will tomorrow right after work though. And i'll let you know. thank you for the suggestion.

 

I also notice a strange little motor sound coming from the trunk by the fuel tank cap when i tried to use the power door lock switch!! What is happening? please help

 

Most likely the locking motor for the fuel filler door.
Any update on the fuse check?

 

I checked the fuses today and all of them seems to be fine.
Then it must the locking motor for the fuel filler door that you mentioned, but what is that anyway, and can i fix it? thnx so much

 

Check the wiring going into the door happened to me a while ago a wire had corroded off.

 

it's the vacuum pump. needs to be replaced. exact same thing happened to me with identical symptoms. about $400 or so to fix at a non-dealer garage

 

Thank ok2000A8, yes it is the vacumm pump, the dealer wants $1000 to fix it. i'll try calling the wrecking yards.

 

hi i am having problem with all my door lock on my 99 audi a4.it won't lock from the inside.is there a fuse for it.