other potential issues... (i too had issues with Homelink)

1) make sure the hand held remote has new batteries
2) make sure the hand held remote is on the "right" frequency. Some remotes provide two choices
3) if (1) and (2) do not fix the issue, try another hand held remote

It can be a ridiculous process (it took me like 30 minutes of trying different combinations b/f the car finally finally took the signals)