09 Megane Dynamique Coupe Keyless Issue

I have recently bought a 09 coupe and the keyless lock/unlock was working 100% and now it has stopped.

Doesn't unlock when i touch the handle or auto lock when i walk away from the car with the key.

Any idea's what the issue could be? I'll try changing the battery in the key and see what difference that makes.

09 Megane Dynamique Coupe Keyless Issue