Details of the RESET PROCEDURE I used
1) Reset by manually unlocking the car door and whilst the key is still in the door, press the button, lock/unlock button. This re-syncs the electronics if it is time that has caused the car to forget the remote.
2) As the remote uses a rolling code (new code every lock cycle) if the remote sender has been activated more than 256 times and less than 1024 times with the receiver out of range or while the vehicle battery is disconnected the unit must be resynchronized as follows:
- Switch on the ignition (ignition key must have the correct transponder).
- Switch off the ignition.
- Remove the key and press the remote sender button within 6 seconds after the ignition key has been removed
The activation counter will then be reset to zero.
3) If the fault lies with the remote, you can reset the remote fob's chip by inserting the button battery in reverse (wrong way round) for a couple of seconds. (ie -+, +-)
You should try these in order, but note that if 3) is used, 1) and 2) will need to be run again.
If none of those work, you probably need a new remote!