Remote Central Locking/Alarm Fob Battery Replaced & Now Not Working

[steve5s]

Had previously posted this in the Misc section but have been advised to post it here.

1998 A4 TDI Avant

Last week one of my remotes was not unlocking the car without it being pressed three of four time. I suspected the battery, what with it now getting colder. Now I know this is my own fault but I took out one of the batteries to get the correct replacements. I guess it was out for four days. I've now replaced both batteries and yes you guessed it looks like the remote fob has lost its coding with the main unit. Does this mean I've got no choice but to visit a stealer and be charge half hours labour to have it recoded or can I do some magic myself?

 

[dsmclark40v]

if you have got two keys you can do it like this
1). Switch ignition on with key that is already programmed
2). Manually lock the driver's door with new key / remote.
Within 5 seconds
3). Press the unlock button on the remote once. The horn sounds once.
Wait 5 seconds
4). Press the unlock button once. Vehicle unlocks.
5). Remove both keys and try.

and as far as i know the other key doesn't have to be a remote key.
hope this helps.

 

[inigoj]

Probably best to resynch both keys, then you dont overwrite one of them.

Same proceedure but 2 presses for the second key with a one second interval.

 

[steve5s]

Fantastic, works perfectly now. Many many thanks Steve