I recently replaced my automatic garage door.

Here is what I found. Hope it is helpful.

NOTE:
The garage door remote transmitters come in two types: fixed code and rolling code. Each type has its own programming method, and each
method covered in the owner's manual. If you have concerns about the HomeLink unit, have the customer contact the HomeLink assistance desk at 800-355-3515. On the internet, go to www. Homelink. Com.

If the HomeLink remote control system will not open the garage, do this:

1. Clear any previously learned codes by pressing and holding the two outside buttons (A) on the HomeLink unit (B) for about 20 seconds. When the red indicator (C) on the unit starts blinking, release the buttons.

2. Point the test remote transmitter (A) straight up exactly 101.6 mm (4-0 in.) Away from the HomeLink unit (B).

3 Press and hold the button on the test remote transmitter and one of the buttons (C) on the HomeLink unit at the same time.

4. Wait about 20 seconds while watching the red indicator on the HomeLink unit.
If the red indicator starts blinking slowly and then blinks faster, the unit is OK. Release the buttons, then clear the learned code (see step 4).