One problem that people may be having is holding the garage opener motor 'learn' button TOO long. If you do this, it will erase the codes to ALL your hand-held remote openers issued with the door (As it did on my new 'Lift Master' garage door opener)...PLUS any other vehicle Homelink buttons programed.
Be sure to just press the 'learn' button on the garage door opener housing until the little 'learn' button light first comes on (if so equipped)...NOT FLASHES. If it flashes, you've erased ALL codes, but not to worry. Repress the 'learn button until the light comes on, press your hand held remote, and the main garage door light bulb will flash once. That means the code has been reset. You will have to repeat the process with your second hand-held remote also, since it's code will have been erased...along with all other vehicles that have been programmed with the same code.
The same may be true for garage door motor housings equipped with the 'learn' button with NO button light. Mine has a little green light by the button and I'm not familiar with other openers.
In either case, hold the 'learn' button down for a second or two only, and that should suffice.
Then you can set up your Homelink visor button.
Once you have performed all the steps outlined posted by our learned fellow-member denslexusgx470, press the garage door motor housing 'learn' button until the light comes on (BUT DOESN'T FLASH)..or for a second or two if button has no indicator light) press your now code-free Homelink button on the vehicles visor, until the garage door main light bulb flashes once (Lift Master garage door openers) and presto! Your homelink button will now work.
In my case, the garage door MAIN LIGHT BULB WILL FLASH ONCE, then I know the new programed remote will work. Again, I don't know about other brands of door openers.
One other thing. The vehicle's homelink button should be pressed until the visor light flashes and then the garage door will open/close. Just pressing the button and letting go quickly like a handheld will not work (At least not for both my Lexus SUV RX and ES Sedan). I just hold the visor button down and when it flashes rapidly the door operates normally.
When I purchased my second Lexus with the Homelink I just did the simple routine outlined above and now I have 4 garage remotes. One Homelink in each vehicle, plus the 2 hand-held/visor clipped) remotes.
This comes in handy when my wife and I are out and one of the kids comes over and needs to get into the garage for something using my hand-held garage remote,(like my son borrowing my riding mower...LOL) or if we have a nasty weather day and my daughter wants to take the baby in the house out of the weather, she uses my wife's remote, or either of them can swing by the house to take delivery of a bulky item to store in the garage when we are both out.
