i opened my key to put new battery in and now the sensor isnt working at all i need a sensor code?

rosemary, January 2010

No code needed.
Get in car, close door, hold the central locking button down ( the one by the handbrake or on the dash, not the one on the key) for at least ten seconds. The doors should lock then unlock. Quickly (within ten seconds) point the key at the receiver (above the rear view mirror) and press the button on the key. The doors should lock then unlock.
Exit car and try remote.

laguna, January 2010

I would first check that there was only one battery in the fob, mine had two,CR2025 and looks like a 10p coin there may well be another on the bottom clipped it to the fob,check again and make sure they are the wright way round.Don't make assumptions until you redo your work.Good luck.

a, January 2010