I have a 2002 GMC Sierra 2500HD. I bought it used and it did not have any keyless entry remotes. It is an SLT, so I believe it must have the capability. I've followed the procedure I've found on many sites to Close the doors, Hold the unlock button the driver's door, turn the ignition ON,OFF,ON,OFF, then release the unlock button...but the process does not cause the truck to cycle the locks as the procedure states it should and therefore is not in programming mode.
