2003 GMC Yukon
1. Close all doors, insert key into ignition do not turn it.
2. Hold the UNLOCK button on the driver's side door DO NOT RELEASE until instructed to do so in step 4.
3. Quickly turn ignition from ON to OFF twice. (Do not start the car, ON is the position just before starting and OFF is where you can remove the key)
4. RELEASE the UNLOCK button. The locks will now cycle from lock to unlock signaling the vehicle has entered programming mode.
***If the locks cycle before you release the unlock button the programming will not work and your vehicle is not in programming mode. Repeat from step one. If the locks continue to cycle before releasing the procedure is not being followed correctly or something is malfunctioning with the vehicle�s keyless entry system.
5. Push and hold the LOCK and UNLOCK button at the same time on the first remote you wish to program. Hold the buttons down together until the vehicle responds by cycling the door locks (you may have to hold the buttons down for up to 5 minutes when programming a new remote � a previously paired remote will pair more quickly)
Repeat the step 5 above for any additional or existing remotes or existing that you wish to program and use on the vehicle at this time.
6. Turn the key to the ON position, which exits programming mode. Programming is now complete. Test all remotes.