They may also need to be synchronized. The procedure is in the owner's manual. From memory: aim the remote at the receiver in the mirror and press the button twice. Within 30 seconds, put the key in the ignition cylinder and turn to position 2. Then remove the key. If that doesn't work, change the batteries. If they still won't synchronize, you may have bad keys or a replaced RCL and IFI computer which don't match the car.