How do you program keyless remote for 2003 GMC sierra?

Answer 1

1. Close all the vehicle doors.
2. Insert the ignition key into the ignition lock cylinder - do not turn ignition switch.
3. Press and hold the DOOR unlock switch (This is the switch on the door, NOT the remote).
4. While holding the DOOR lock switch in the unlock position, cycle the ignition ON, OFF, ON, OFF ON, OFF. (3 TIMES)
5. Release the DOOR unlock switch. The doors will lock and unlock one time to confirm the program mode is actuated. Remove the key from the ignition.
6. Simultaneously press and hold the LOCK button and the UNLOCK button on one key less remote for approximately 15 seconds, the doors will lock and unlock to confirm the programming of that transmitter.
7. Repeat the previous step to program up to four transmitters. Reprogram any existing remotes at this time as they have been erased.
8. Turn the ignition switch to the ON (one more click forward) position in order to exit the keyless entry transmitter mode.
9. Operate the transmitter functions in order to verify correct system operation.