So I've recently bought a 2002 Vauxhall Corsa, the battery in the key fob was dead so I bought a new Cr2032 battery and replaced it, admittedly it took abit to get into but I'm pretty sure I only damaged the casing and not the internals. After replacing the battery I tried it on the car to see if it un/locked, it didn't so I then recalibrated the key (turning it in the ignition to accessories for 10 mins 30 seconds 3x) after I tried to lock my car but it locked and unlocked again, I tried several times with no success, I then tried locking it through the key hole in the door but it only locked the driver's door not all doors as usual. I have never seen this problem before and really need advice.

Update: Problem solved, went out to the car first thing this morning and unlocked it through the door and tried locking it through the key, worked first try, no problem, think it's just a broken unlock button

Hi

Glad you managed to resolve it.
It happens on Nissan and Renault where the button actually comes away from the circuit board and can be soldered back on.

 

Have the same problem with my Astra key, caught the battery carriage when changing battery, now got to get soldering iron out. But it does still work ok with the key in the door lock. 

That is the Law according to Sod AndyR 😞

 

Oh and how!!! 

It still unlocks on the key and it starts and runs, so it's just a minor detail. 😊

Best not to fiddle with it then just in case 🙂