Hi I have a 2001 galaxy tdi 1.8. The other day the key fob stopped locking and unlocking the doors. I thought it maybe the batteries but have noticed that the light flashes when I press the button. Does anyone know if I should just change the batteries first, if so which batteries do I need, to see if this works or does it sound like it could be something else. I have to use the key manually and on a couple of occasions when unlocking or locking the door it will put front windows down / up. Many thanks.