Key Fob Battery Replacement, Now It Won't Work.

[Sueps]

Hi all,

 

Sorry if this topic has been covered before, I tried to use the search box but for some reason the words "key" and "fob" are forbidden (!?).

 

I just needed yesterday to replace the battery in my key fob but now I have the darn thing won't work. I'm fairly certain I've replaced it before with no problems as I've been carrying a spare battery around in case it happened again, and I would only have found out which type of battery it was by replacing it once. Hope that makes sense! Weve checked the battery with a multi-meter and it's reading about 3.25v.

 

I saw something somewhere about pressing the lock button with the key in the ignition, turning the ignition till the dash lights come on and holding the button for several seconds. I held it for about 30 seconds but it didn't work.

 

Does anyone have any ideas please? My c5 is a 2002 if that helps.

 

Thanks, Sue.

[paul.h]

If you have the car handbook it will say how to initialise the fob after replacing the battery. In our 2007 C5 handbook it gives to turn on the ignition with the key and then immediately press the fob lock button until it locks the doors which can take about 10 seconds. The Haynes manual gives the same so it must also apply to earlier cars.

 

If this does not work then remove the battery on the fob and try again.

[YOG]

I have a 2002 2.2 Auto.

 

Owner's Handbook:

 

The remote control must be reinitialised after changing the batteries. For that, switch on the ignition and then press one of the three buttons of your remote control.

 

Remote control battery used up

Accompanied by an audible signal, this information is provided by a message on the multifunction screen.

[Sueps]

Hello,

 

Thanks for the replies. I tried the reinitialising but couldn't get it to work. I can't find anything in my manual about changing the battery and reinitialising the key.

 

Then I remembered that I'd had a second, rather tatty, key with the car so swapped the insides of them. Now, for some strange reason, both of them work!

 

Anyway, thanks again.

 

Have seen a couple of threads on here about "limp mode" which my husband's c5 does, so will have a look at them!

[paul.h]

In the handbook the fob battery replacement will only be a couple of lines in the section on the keys/remote so can easily be missed.

 

If you provide a bit more info on your other C5 and its problems we may be able to help.