Hi all, hope you can help. I replaced the battery in my key fob today. The fob was working before but the range seemed poor. Fitted a new battery to the fob, now the buttons do nothing. Looked in the manual for the guide on how to get the car to relearn the key ie turn from 0 to 2 4 times within 6 seconds etc but I never get the chime to say its in programming mode. Not sure if I'm doing it incorrectly,I've tried so many times so I thought I would see if anyone here has any ideas? Car is a 2008 mk2.5 1.8tdci. Thanks for any suggestions 

2 hours ago, mrizzo1uk said:

Hi all, hope you can help. I replaced the battery in my key fob today.

The battery you threw out, did you test it by any chance? They should be pushing out 3.3v when new, and should work down to 3v. Once below that, it'll give issues. Also, just because a battery is 'new' you should still test it... That'll rule out the most basic fault.

As Stephen has said, measure the voltage of the battery with a multimeter to check it is good. I trust that it is Duracell or Panasonic and not a Poundland^* special.

I have to ask the question are you absolutely sure the battery is in the right way up ?

If your happy with the condition of the battery and it's fitment then try the following:

Standing outside the car, use the metal key and put it in the lock. Turn it to the lock position and then back to the unlock position. Do this lock/unlock 3 times and then re-try the remote.

 

 

^{* Poundland now renamed to "Ten Poundland" due to recent inflation !!}

 

Thanks for the replies. The battery is Duracell and checked with a multimeter and its good. Definitely the correct way up. I will try the method unofix mentions. I hadn't tried this as the manual said to do it inside the car using the key to go from 0 to 2 4 times etc but I never get the chime to say its in programming mode. Everything was working before I changed the battery so don't think it's a module issue

You may still need to reprogramme the keys using the method you have been using. The lock/unlock just clears the system

OK so tried that and it didn't work so managed to find my spare key that I don't use as whoever owned the car before me absolutely mullered it trying to get it open and now it won't stay in one piece. However when I opened that up and compared the metal contacts I could tell that one of the contacts in the better key was out of shape. I tried to re shape it but it just snapped so i swapped it with the other one and now i have one key that works as it should! I will just keep the spare as it is as I assume that will still be ok to start the car just the central locking buttons won't work.

Thanks for your help everyone, atleast I know how to reprogramme it if I ever need to

depending on make model the consensus is 2-4-6-8 turns of the key to position2 before it chimes then when it does press any button on the fob.