Driver's door locks and unlocks with key, but none of the other 3 doors lock or unlock.
This car has power locks, and vacuum hoses going to the doors.
Questions: Is there a vacuum pump? If so, where is it? How to make it work? Where to find replacement (new or rebuilt)?
My experience is with a car 12 years older than yours, but may still be relevant.
The system is often referred to as vacuum operated, but this is a misnomer. It is actually a bi-pressure system, pressure above atmosphere unlocks, pressure below atmosphere locks. The pump is located in the far left side of the trunk, inside a thick noise insulating clamshell.
Several things can go wrong. A very likely problem is that the switch in the driver's door is malfunctioning, so that the pump never gets a "lock" or "unlock" request. Do you have keyless entry? If so, can you lock or unlock the doors with the remote?
Air hoses can break, in which case the pump will run for about 30 seconds trying to lock or unlock, then shut off. In this case you will hear the pump running, sounds kind of like an aquarium pump. On the Golf a common spot for a hose break is where the hose goes into the hatch. Don't know if there are any common trouble spots for the Jetta.
If you find that the pump is broken, your best bet is to find a replacement at a junk yard. The same pump was used in a variety of Golfs, Jettas and Passats throughout the 90'a.
I should add that this is the location for the A3 Jettas. I believe the US '99 Jetta was still an A3, while Germany had already gotten the A4's. I do not know where the pump is on the A4 cars, not even sure if they used the bi-pressure system still.
First off, are you unlocking the door lock twice? Does your remote transmitter unlock the doors?
When you try to unlock the doors, or lock them, do you hear a pump running in the trunk on the left side? Listen for hissing too near the door hinges at both the front and rear doors. May be a disconnected vacuum hose/tubing there.
Maybe it is the microswitch at the left door's latch/lock??? Do you have a switch on the dash that activates the door locks?
Fuse? Anything else not functioning electrically?
Wiring at the driver's door? You might have to peel back the rubber protective wiring harness and inspect the wires for any broken ones.
Good Luck and let us know what you find!
later, dave (One out of many Daves)
read here:
Check your fuses and for broken wires in door jam on LF door.
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