How does the auto-locking-at-10Mph work?

**lucasvdb** · 21-10-2009,12:55 PM

My 2003 A6 1.9Tdi Multitronic has this faeture enabled however it seems a bit unreliable. It works for weeks, then stops working for weeks, then suddenly works for weeks again.

Where is the decision made? In the 'Convenience Module'?
Where does it get the 10Mph from? I assume an ABS sensor, but in which weel?

Does using the inside lock/unlock switch interfere with the set-up?

The speedometer is working correctly and there are no ABS warning lights.

Lucas

**Crasher** · 21-10-2009,01:08 PM

Have you had any water ingress into the passenger’s side? The convenience unit is under the passenger’s front floor and can get wet due to the well covered plenum chamber drain issue. When it is not working, you could to take it to someone who has a diagnostic computer and they can look at the data blocks of the convenience unit to see if the speed signal is missing.

**NickPicks** · 21-10-2009,02:44 PM

Does using the inside lock/unlock switch interfere with the set-up?

If you have stopped, and used the unlock button on the door to let someone get in / out, then the car will not re-lock itself as you pull away again.

If you stopped and re-started the engine, then it will re-lock as it should.

**kite** · 21-10-2009,02:46 PM

Originally Posted by NickPicks

If you have stopped, and used the unlock button on the door to let someone get in / out, then the car will not re-lock itself as you pull away again.

If you stopped and re-started the engine, then it will re-lock as it should.

My A4 relocks when you pull away again

**Crasher** · 21-10-2009,03:44 PM

My Octavia re-locks again when you pull away (without stopping and re-starting the engine), whichever door has been opened.

**lucasvdb** · 21-10-2009,04:01 PM

The car suffered from the plenum chamber syndrome indeed however that was long before the auto-locking option was enabled, and there are no other issues around the central locking i.e. windows opening by themselves.

I have two theories:

1. The speed sensor is in one of the front wheels as last Friday I had the tyres changed. But the effect was not immediate. The auto-locking stopped working on Monday...Sat and Sun was OK!
2. The speed signal is going through one of the looms in the boot as at one occasion the feature came back when I had touched those wires. However I cannot repeat that...

Lucas

**Crasher** · 21-10-2009,06:05 PM

The speed signal comes from the box and is the same one the dash and ABS see.

**WesleyP** · 21-10-2009,07:58 PM

How do you get it to work in the first place?

**Crasher** · 21-10-2009,08:23 PM

By recoding the convenience unit using VAG-COM or similar systems.

**lucasvdb** · 13-11-2009,03:05 PM

I had my first experience with the VAG-COM shareware yesterday...

There were no errors reported however suddenly the auto-locking started to work again....

What a co-incidence!