Hi. I`m new to the forum, having recently purchased an A4 1.9 TDI for the princely sum of 500 euros. A very nice car (especially considering the price...) and the only real problem I have is with central locking (using the key..I don't have a remote) . When I first purchased the car it worked about 90% of the time, but has gradually reduced to about 10% of the time. Sometimes I'll unlock the drivers door and none of the others will activate, but when I arrive at my destination all doors will have unlocked at some point. I imagine it can't be the pump impeller as it does work occasionally. Any clues as to where to start looking for the problem would be greatly appreciated.Thanks.

 

If it's anything like the American models, the pump is in the truck on the passenger side between the tail light and wheel well. You just have to pull the truck liner and stuff out of the way.

 

Troubleshooting is all about isolatiing things. Disconnect the pump, and make it work with your finger over the vacuum fitting. Is there always good vacuum there? If so, you have a leak somewhere in the system. You have to start adding things. Does the gas tank door alway unlock if it's the only thing connected? Go from there.

 

Thanks for the prompt replies guys. The thing is I've had someone work the key for me while I checked the pump and it appears as though the pump isn't firing. I blew and sucked on the vacuum line and there doesn't appear to be any leaks in the air lines as all doors promptly locked and unlocked. I've yet to remove the door trim but i'd imagine there's some sort of actuator switch in the driver's door? Is there some sort of hidden fuse/relay/management box that controls the system? It's the intermittent nature of the fault that's got me stumped. There doesn't seem to be any rhyme or reason to the problem. It just works and then doesn't work. Thanks again for the replies.