You probably need to reprogramming fob

You'll need the override touch key and your alarm PIN.

1) Hold the two buttons on the alarm fob until the LED on the fob stays on

2) Turn the ignition on and off three times in a row ( don't start the engine, just so the dash lights show)

The LED on the dash will come on then go off after about 3 seconds

3) Turn the ignition on - the LED will flash - you have to count the flashes - these correspond to the alarm PIN - when the LED has flashed the first number turn off the ignition.

4) Repeat step 3 for all four number of the pin.

5) Turn the ignition on ( the LED on the dash should be off ) and touch the override key in the override socket

The LED will come on and stay on

6) Press the big button on the alarm fob

Your fob should now be programmed.

Good luck - if you muck up the counting of flashes, just wait ten seconds and start again - you won't ever block your alarm no matter how many times you give this a go.