S2 ABY - Central Locking Pumps - Fault Queries

[macspring]

On my 95 ABY Avant I have a a faulty central locking pump, the part number is 4A0 862 257 J

On my 99 ABC Cabrio, the Centaal Locking unit is also faulty and the car's part number is 8L0 862 257 G.

Copied the info below from another forum, don't know how accurate it is ?

8L0862257 early remote pump with limited functions e.g wont operate door flashing led's
8L0862257 'A' early non remote pump
8L0862257 'H' later 98-99 non remote pump
8L0862257 'G' later remote pump for use with 2 button fob
8L0862257 'P' + 8D0862257 'E' facelift pumps for use with 3 button fob.

What I was wondering is, what's the significance of the start of the two different sets of part numbers, i.e. 4A0 and 8L0 ?

As I understand it, regardless of the different pumps / part numbers, it is the actual small pump inside the Central Locking unit which goes faulty, and so all one needs to do is take your car's faulty Central Locking unit and replace the pump inside from another Central Locking unit, with not necessarily the same part number.

Does anyone have any previous experience with resolving Central Locking Pumps for these B4 cars ?

http://www.audiworld.com/tech/elec149.shtml

http://www.audi-sport.net/vb/a4-s4-forum-b5-chassis/45194-a4-central-locking-pump-faulty.html

Any comments or feedback from people who've already BTDT would be greatly appreciated.

Thanks.

[PhantomS2]

Central locking pumps

I have just repaired my 4A0 pump after an 18 month saga.

The only decent resource I found was this site in Germany, they list the various pumps and the functinality of each

http://www.digakom.de/katalog.php?TYP_SORT=A&KAT_SORT=80/90/200

They list 4A0, 8D0 and 8L0 types, with some tech info. They also supply replacement relays and key fobs. I found it is generally the relays that are at fault, although I have one sick motor. Interested in getting hold of broken units to canabalise / repair for learning experience.

I have a test loom for 4A0 units and also buzzed out a circuit schematic for the 862 257A which the 3B S2 has.

Hope this helps !

[macspring]

Thanks for replying, I thought I was becoming invisible !

No replies to this thread until now.

Will check the info in you reply. Thanks again.

[R31LLY]

them things are crazy i had one and it put hazzard lights on not indicators at random, i swapped it with my mates 80 tdi and it worked fine, they seem to create different sysptoms on both cars we had, on his car the immobiliser didnt work, at least they are not too expensive lol

[newsh]

If you have problems with the pump and any related functions like courtesy lights, its worth checking the wiring to the pump which runs under the carpet on the driver's side. I had broken wires (just below the right foot). The insulation had cracked where the wires go into the white plastic cable cover and the damp had got in and corroded the copper. The result was the wire was high resistance, you could measure the correct voltage at the pump but the motor would not run as the wire would not pass enough current.

[macspring]

Newsh,

Thanks for the reminder, when you say now it I remember your thread about it, it was a very obscure lengthy fault for you.

Will keep it in my mind and while checking it out.

Thanks again.