1997 Chevrolet Astro Owner's Manual - Page 128

Your vehicle's engine should be turned off while programming the transmitter. Follow these steps to program up to three channels: 1. If you have previously programmed a universal channel, proceed to Step 2. Otherwise, hold down the two outside buttons on the universal transmitter until the red light begins to flash rapidly (approximately 20 seconds). Then release the buttons. This procedure initializes the memory and erases any previous settings for all three channels. 2. Hold the end of the hand-held transmitter against the bottom surface of the universal transmitter so that you can still see the red light. 3. Decide which one of the three channelsyou want to program. Using both hands, press the hand-held transmitter button and the desired button on the universal transmitter. Continue to hold both buttons through Step 4. 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 garagedoor 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 hand-held transmitter in case you need to erase and reprogram the universal transmitter. 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. 4. Hold down both buttons until you see the red light on the universal transmitter flash rapidly. The rapid flashing, which could take up to 90 seconds, indicates that the universal transmitter has been programmed. Release both buttons once the light starts to flash rapidly. 2-54