CHEVROLET\GMC SERVICE CAMPAIGN: SEE DOCUMENT SEARCH BUTTON FOR OWNER LETTER. ENHANCED CALIBRATION FOR TRANSMISSION OVERHEAT IN EXTREME COLD AIR TEMPERATURES. LOCATED IN CERTAIN US COLD WEATHER STATES; ALBERTA, BRITISH COLUMBIA, MANITOBA, NEW FOUNDLAND, NORTHWEST TERRITORIES, ONTARIO, QUEBEC, SASKATCHEWAN, AND YUKON. SILVERADO HD AND SIERRA HD 2006-2008. *PE CSC LETTER WAS RECEIVED (ONLY). UPDATED. *PE PROGRAM BEEN REVISED TO EXPIRE 9/30/11. *PE
