Sorry, the NHTSA has not posted this TSB document yet.
You can still get the detailed info from Chevrolet for this TSB. Call your local Chevrolet dealer's service department & ask for a copy of TSB# PB-11035.
GM SERVICE CAMPAIGN: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. 2011 SILVERADO/SIERRA. SOME TRUCKS MAY HAVE BEEN BUILT WITHOUT A NOISE LABEL ON THE DOOR. *RM