Insert your current, working key into the ignition and turn it to the "ON" position but don't start the engine.
While in the "ON" position, wait for the security indicator light on the dashboard to turn off (after about 3 seconds).
Within five seconds of the security light turning off, press and hold the "Lock" button on the keyless remote control.
Hold the "Lock" button for at least 15 seconds, or until the security light on the dashboard starts blinking.
Release the "Lock" button and press and hold the "Unlock" button on the remote for at least 15 seconds, or until the security light blinks again.
The remote should now be programmed and you should hear the door locks cycle as confirmation.
To program additional remotes, repeat the steps above within five seconds of programming the first remote.
After programming the last desired remote, turn off the ignition switch.
It's important to note that the programming process may vary slightly depending on the exact model and trim level of your 2005 Honda Odyssey. If you encounter any difficulties, you may want to refer to your owner's manual for more detailed instructions.
