1998 GMC Yukon Owner's Manual - Page 144

If you have trouble programming the universal transmitter, make sure that you have followed the directions exactly as described and that the battery in the hand-held transmitter is not dead. If you still cannot program it, rotate the hand-held transmitter end over end and try again. The universal transmitter may not work with older garage door openers that do not meet current Federal Consumer Safety Standards. If you cannot program the transmitter after repeated attempts, consult your GM dealer. Be sure to keep the original h'and-held transmitter in case you need to erase and reprogram the universal transmitter. b Erasing Channels To erase all three programmed channels, hold down the two outside buttons until the red light begins to flash. Individual channels cannot be erased, but can be reprogrammed using the procedure for programming the transmitter explained earlier. Training a Garage Opener with a "Rolling Code" Feature If you programmed the universal transmitter, but the gwage door will not open, and if your garage door opener was manufactured after 1995, your garage door may have a security feature that changes the "code" of your garage door opener every time it is opened closed. or To determine if your garage door opener has this rolling code" feature, press the appropriate button on bC Operating the Transmitter Press and hold the appropriate button on the universal transmitter. The red light comes on while the signal is being transmitted. Note that the effective transmission range of the universal transmitter may differ from the hand-held transmitter and from one channel to another. the universal transmitter that was programmed. If the red light flashes rapidly for one totwo seconds, then turns solid, your garage door opener has this feature. 2-66