Important: Due to component variability, the vehicle theft deterrent (VTD) system must have the learn procedure performed regardless, if the vehicle starts on the first ignition cycle after a VTD repair.
All codes in the theft deterrent module must be cleared for a relearn.Important: 
   •  The body control module (BCM) must be programmed with the proper   RPO
 configurations before performing learn procedures. Refer to BCM Programming/RPO
    Configuration in Body Control System.    •  If replacing the BCM with a GM Service Parts Operations (SPO)   replacement
 part, the module will learn Passlock™ sensor  data code   immediately.
     The existing PCM however, must learn the new fuel  continue   password
 when    the  BCM is replaced.    •  If replacing a PCM with a GM Service Parts Operations (SPO) replacement
   part, after programming, these modules will learn the incoming fuel continue
        password immediately upon receipt of a password message. Once a password
       message  is received, and a password is learned, a learn procedure
must      be   performed  to change this password again. A PCM which has been
previously        installed  in another vehicle will have learned the other
vehicle's  fuel      continue  password  and will require a learn procedure
after programming      to  learn the  current  vehicle's password. 
Use these procedures after replacing:
| • | Passlock™ Sensor | 
| • | BCM | 
| • | PCM | 
| • | Tech 2 | 
| • | Techline terminal with current Service Programming System (SPS) software | 
None
Important: The vehicle learns the Passlock™ Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.