Faulty key fob

[Stembo69]

My key fob seems to have am ind of its own. Sometimes it will open the car from 20 yards, others i have to walk around next to it pressing the button until it opens.
If this is a faulty battery in the fob, when i change it do i need to re-program it or will it work straight away?
Alternatively, could it be faulty sensors in the car?
Thanks

[paxo89]

mine used to do this, whacked a new battery in and it works fine now:y:

[paxo89]

also try to point it at the receiver (black thing near interior light)