One method.
To synchronize the key fob transmitter
This may be required after replacing the batteries or when receiving a replacement fob.
Directions as stated in the Owner Manual.
 Aim the transmitters red eye at the vehicle.
 Briefly press the lock or unlock button twice.
 Within 30 seconds, insert the key in the ignition.
 Turn the key to the ON/Run position.
The remote control function should again be operational.

Second method
PROCEDURE
Transmitter programming by the customer is done by performing the following steps: Insert the key into the ignition switch.
1. Press either the lock or unlock button momentarily twice.
2. Turn the key in the ignition switch to the ON/RUN position within 30 seconds.