How do you program a new key a 2003 Honda Pilot?

To program a new key for a 2003 Honda Pilot, you'll need to have the new key and a working master key. Insert the master key into the ignition and turn it to the "On" position without starting the engine. Turn the key to "Off" and remove it, then insert the new key and turn it to "On" for about 10 seconds. After that, turn it back to "Off" and your new key should be programmed.