Don't know if this will work for you guys in the US but it surely worked the first time on my JDM Spec-B .............
UNLOCKING DOORS USING THE KEYLESS ENTRY SYSTEM WITH A SECURITY CODE.
Preparation
1. Have the driver's door unlocked. 2 Hold the door handle up for 6 secs.
3. A buzzer will begin to sound.
4. While the buzzer is sounding, press the remote control unlock button & the buzzer will stop. The prep is now complete. (The buzzer will sound for 30 secs)
Setting
Illustration using 3246 as the 4 Digit Security Code
1. Lift & release the door handle 3 times -> WAIT FOR BUZZER -> Lift & release twice -> WAIT FOR BUZZER -> Lift & release 4 times -> WAIT FOR BUZZER -> Lift & release 6 times.
2. When the buzzer sounds intermittently, repeat the same procedure above within 30 secs.
*If you make a mistake when setting the security code, lock the driver's door to cancel the setting procedure and start over from no. 1 preparation procedure.
* As a safety feature you will not be able to set all 4 digits to 0000,1111,2222 etc or consecutive nums such as 1234 etc.
Now do a trail & see what happens (Use your own 4 digit security code)
Eg.
1. Lift & release the door handle 3 times -> WAIT FOR BUZZER -> Lift & release twice -> WAIT FOR BUZZER -> Lift & release 4 times -> WAIT FOR BUZZER -> Lift & release 6 times.
Now, if you are at the beach, you can hide your keys under your mat or in your glovebox, lock the car with the switch on the driver's door, and simply use a 4-digit code to enter the car when you return.