View Full Version : URGENT help please! Alarm/key re-sync issue

26-08-2009, 10:23 AM

Hoping someone can help. The battery on my keyfob died so i changed it but the central locking still wouldn't unlock. I read up on it and figured that it must need to be re-sync'd to the car. I have a copy of VAG-COM so I followed the procedure from the ross-tech site for re-coding the key.


I did this yeterday evening and it seemed to work fine. The car locked ok using the key fob after following this process.

Problem is, this morning I walked up to the car and unlocked it using the key fob, which again worked fine, but the alarm went off. I rushed over and put the key in the ignition, turned it on and the alarm didn't go off! This is at 7am with loads of unhappy neighbours looking on! Nothing would work to turn the alarm off.

I didn't know what to do so i ran into the house, grabbed my laptop with VAG COM on and drove off with the alarm sounding - just to get away from the houses. Eventually it just stopped on it's own after 5-10 mins. I got to work and ran a VAG-COM scan - no faults found on module 46 Cent. Conv.

I repeated the process above for re-syncing the key fob but I was so scared of the alarm sounding for 10 mins in the work car park if I unlocked the car, that i've just left it locked for now. I'm excpecting that when I do unlock it later today, the alarm will go off and I won't be able to stop it.

Does anyone have any clues how to fix this?

I'd be VERY grateful for any help!

26-08-2009, 10:45 AM
You could have a faulty contact switch in any of the 5 door lock or the bonnet. I would check the bonnet. Also ccm wiring wet/damage can cause similar problem. It shouldn't be anything to do with fobs because if they open the doors they should also switch off the alarm. Was alarm working before the fob batteries went flat.

26-08-2009, 11:20 AM

Thanks for the reply.

Everything was working fine before. The key-fob just stopped working so I had to unlock/lock the car manually with the key in the drivers door. Central locking and alarm seemed to be fine, same as before the fob died.

I replaced the battery and the fob still wouldn't work so I tried the re-sync as described above and now all of these problems with the alarm have started. I'm thinking I haven't re-sync'd it properly with Vag-Com?

I saw a post a bit further down the page with an alternative way of sync'ing the key here:


I may try that and see if it works?

26-08-2009, 02:21 PM

Tried again at lunch time. Alarm did go off again.

I ran another scan and got an error on module 46

01179 - Incorrect key programming

35-00- -

So it's definately to do with how I programmed the key. I tried to follow the procedure but I don't get any sign either of vag-com or by way of the car horn/lights to suggest the key code sync has worked.

I therefore tried to set the code in adaptions back to 00 (factory default) so that the key fob would reset.

I got out and tried to lock the car with the fob and it wouldn't, so I locked it manually again with the key in the lock and everything seemed to set ok.

My lunch break was over so i didn't want to risk trying to unlock it again in case the alarm still goes off.

Anyone got any further ideas?

26-08-2009, 07:29 PM
Further update:

This is just weird.

Went back to the car after work - alarm went off again. I was at my wits end so decided to drive straight to the main dealer to see if they could re-sync the key properly.

They re-synch'd it......I paid my 20 odd quid, picked up the key and walked over to the car and try to unlock it with the fob........ Nothing happens........ I unlock and lock it with the key manually and that seems ok - no alarm problems.

I go back in and explain this to the reception guy (not the tech who worked on it who has now gone home). He comes out and has a go and can't understand what's wrong. According to the worksheet or whatever, it should be done.

I have a play with the key, locking/unlocking the car manually, and something happened which was happening before I had a go at re-synching the fob. The drivers door alone locked as opposed to all doors - it's as if something don't quite "catch". I unlocked it, tried it again.....same thing. Tried it again, then this time it catches and the central locking locks all of the doors. The remote locking doesn't work at all though with the key fob. (The dealer refunded my money by the way).

So basically, it appears that the re-synch done by the dealer has reverted the key fob back to how it was before I changed it with Vag-com but something else is wrong which is causing the above symptoms with sporadic central locking with the key manually and no remote locking.

I just don't understand whats happening at all? Mechanically, it seems there is no problem but something else is going on which I can't make head nor tail of???????


09-09-2009, 12:31 AM
What model is your car? and what year?

Your best bet is to take the battery connectors off the car and keyfob, wait for half and hour to an hour and give that a try.... it just may be an error in your ecu.

What is your location? maybe i can help you out.

12-09-2009, 12:42 AM
Taurus, I think it's a MkIV Golf or Bora.
This is very weird. I'm surprised it let you drive away with the alarm going.

You could try the non-vag-com re-sync of the keys. I think you put the key in the ignition and turn it on (don't start engine) then press and hold the unlock on the remote for about 5-10sec. You might need to clear the "dodgy key" fault code before it lets you do that. EDIT: I remember somewhere that if you bugger up key syncing twice or more it doesn't let you re-code for a few hours or something.

Do you have a spare key you could use?

Does the car lock with the remote? Or with the key? when it does lock, do the indicators flash?

I think it could be a door microswitch problem - quite common - but not heard symptoms like this before, and vag-com would prob mention it too.

If you need to lock the car overnight and not have the alarm go off, open the rear passenger door (drivers side) and reach through to the drivers electric window/door lock console thing on the drivers door and press lock - all the nobs should go down then climb out and close the rear door and the door's locked (though with no alarm, interior monitoring or deadlocks - so do it at your own risk!!