finchyaj

Hoping someone may be able to diagnose my central locking problem (94 1.8 Saloon). Central locking packed up a few days ago and before I buy a new pump just wanted someone to confirm if they think it's the pump. When the door/boot is locked the alarm still chirps but no other doors lock. There's no sound from the central locking pump at all (as far as I can hear). I've had the pump out and open. The impeller is in one piece and there's no obvious issues apart from one of the rubber tubing joins has split slightly. Although I assume I would still hear the unit operating but just not actually operating the locks. Another post did mention having a heavy load in the boot which I've had before the problems began. Could this be the cause and if so what would it have broken. Any help will be much appreciated before parting with my hard earned cash. Cheers.

edwoodca

Don't think this will help, because you say you don't hear the pump working, regardless of the locks moving... I found a hose on the right side hinge of my trunk that had come off, disabling 2 of my door locks and the trunk lock. I saw the one of the left side hinge was fine, so I just made the right side match, and my problem was solved. Good luck, bud.

turbo510

You must have one of the earliest A4s if it is a '94.

According to my schematic for a '96, the central locking is supplied with battery power on three different wires, through three fuses. These are numbered S6 (5A), S14 (10A), and S111 (15A). That one supplies current through the biggest wire (red/black). I would assume that one carries the motor current, so check that fuse, then wire at the connector. It is a "terminal 30" circuit, so it is powered all the time. Your central locking module is at least partly working if you get the chirp when locking.

DaveInSaltLake

It's possible that the electric motor that drives the vacuum pump is burnt out. I would check for voltage on the leads that supply power to the pump while it's supposed to be running.

I have some replacement parts for those units if you end up needing some.

finchyaj

Just to update I ended up buying a pump from ebay for £30 which sorted the problem. Not sure what went wrong on the old one.

amar.roy

Dear Members,

I am new here. I got this car couple of years ago. I made peace with the fact that remote key fob did not work and getting them fixed will cost me a lot.
Past Scenario.
In order unlock all doors I had to insert the key for ignition and turn it on. When I was in the car central locking button on the drivers door worked just fine as I hear the locking sound. Upon exiting the car, I used to hear the beautiful and satisfactory sound of locking and all doors including the fuel flap, by manually turning the key and locking the driver side door. The flashing antitheft alarm worked fine.
Current Scenario.
Inserting the key for ignition and turning it on does not unlock all doors. When I am in the car central locking button on the drivers door work's just fine as I hear the locking sound. However, upon exiting the car, and by manually turning the key and locking the driver side door only locks the driver's door and it does not lock all doors or the fuel flap. The flashing antitheft alarm stopped working.

Can anyone tell me what is the possible cause why I am faced with this scenario as I feel vulnerable by leaving fuel flap unlocked and open to abuse by opportunists.
Any guidance will be greatly appreciated.
Thank in advance
Amar

Cybersombosis

Check to see if there is a broken wire in the door jamb wiring loom. Pull the boot back in the accordion looking rubber boot between the body of the car and door and inspect the wires and look for ones that are broken. Hopefully there is one and you can fix it with a little solder and heat shrink.

Do this and report back your findings. It may be your door lock actuator is it isn’t broken wires. You can lock all the doors with the trunk switch in a pinch.