A4 Central locking system.

[Delinquent]

Just picked up a '98 A4 2.4 SE Auto. Bought on a whim (because it was too cheap not to) from a work colleague, haven't got a clue on Audi's as this is my first, so thinking on my feet to sort a few minor flaws out.

While I wait for a manual to appear, could anyone give me a brief rundown of the central locking system on it? I think I can hear a pump running near the boot if I operate the boot lock (though nothing else happens) so I'm assuming the old vacuum type? Also assuming that as the door lock doesn't create the same noise they have stnd switch mechanism with wire's that break at the door hinge?. Where are the pump and control modules, any fuses - any bits of knowledge handy to save me taking apart bits I don't have to!

Cheers

 

[macca]

certainly on the models with remote locking the control unit is in the right side of the boot, between rear light unit and wheel arch, under the floor, usually wrapped up in a block of foam if i remember.

if you can get hold with someone with vagcom near you on here, you can get them to run a diagnostic check and see if any error codes come up.

 

[Siena]

Sounds like an air leak in the system.

Unfortunately, if left unchecked for long periods of time, the pump runs on too long, and the graphite impeller shatters. if that happens, then you'll need a new pump.

On your model, '98, I'd say you MAY have the twin-vacuum unit, though I can be certain if you PM me a chassis number, or you could tell me if your remote fob has a seperate button to unlock the trunk? If it does, it's a twin-vacuum unit, but if just the lock / unlock (2) buttons, then it's a single-vacuum unit.

I'd advice you to unplug the connector to the pump, Macca has told you the location. At least, if the pump hasn't destroyed itself, it can be salvaged, once you find your leak.

If you need another pump, bear in mind, they're coded to individual key remote fobs, so will need recoding, with VAG-com, or similar.

 

[Delinquent]

Cheers guys, pump located, when I get home I'll whip the lines off and check for suction there, if that's OK I'll start the hunt for air leaks - which given the drivers door lock does not get the pump running will be the first place I'll look!

If it's coded is the pcb "part" of the motor or seperate, I'm sure I've got an old pump motor somewhere I could wire in if it's damaged and seperate.

 

[Delinquent]

Checked the pump, had the seemingly common broken graphite disc in the pump, so will be bodging a pump from a passat or similar into the Audi housing next week.

Just to note, to test the rest of the system I repaired the disc and it worked remarkably well, just glued the halves together with superglue then made a small cross to go in the bottom of the location slots for the drive and epoxied it in place. If I'd known just how well it would hold together I'd have spent a bit more time on it and done it properly, I reckon that would probably outlast the rest of the car with half hours work.