How to program a remote key fob for the Acura RDX (or just about any other Acura).
1. Sit in the car with all doors closed and remotes in hand.
2. Insert a key into the ignition and turn to ON (not start), then firmly press the lock button within 5 seconds.
3. Turn key to ACC within 5 seconds.
4. Repeat steps 2-3 until you hear the door locks cycle (usually on the 4th time, but the doors will not lock). The system is now in programming mode.
5. Press the lock button on each additional key within 5 seconds and you should hear the door locks cycle for each key.
6. Remove the key from the ignition.
Your remotes should now be programmed. Step outside and test each remote.