Acura 3.5 RL Manual page 1241

Power Door Locks
Keyless Transmitter Codes Input Procedure
Storing transmitter codes:
The codes of up to three transmitters can be read into the keyless receiver unit memory.
(If a fourth code is stored, the code which was input first will be erased.)
NOTE: It is important to maintain the time limits between
the steps.
1. Turn the ignition switch ON (II).
2. Within 1 to 4 sec, push the transmitter button with the
transmitter aimed at the receiver (rear window).
3. Within 1 to 4 sec, turn the ignition switch OFF.
4. Within 1 to 4 sec, go to step 5.
5. Repeat step 1.
6. Repeat step 2.
7. Repeat step 3.
8. Within 1 to 4 sec, go to step 9.
9. Repeat step 1.
10. Repeat step 2.
11. Repeat step 3.
12. Within 1 to 4 sec, go to step 13.
13. Repeat step 1 .
14. Repeat step 2.
15. Confirm you can hear the sound of the door lock actu-
ators.
16. Within 9 sec, aim the (first) transmitter whose code
you want to store at the receiver, and press the trans-
mitter button.
17. Repeat step 15.
18. Within 9 sec, aim the (second) transmitter whose
code you want to store at the receiver, and press the
transmitter button.
19. Repeat step 15.
20. Within 9 sec, aim the (third) transmitter whose code
you want to store at the receiver, and press the trans-
mitter button.
21. Repeat step 15.
NOTE: If only one transmitter code is to be stored, delete
steps 18 through 21. If only two transmitter codes are to
be stored, steps 20 and 21 are not necessary.
22. Turn the ignition switch OFF, and pull out the key.
23. Confirm proper operation with the new code(s).