CHEVROLET/GMC: TSB CONTAINS AN OWNER'S NOTIFICATION LETTER. SELECT DOCUMENT SEARCH BUTTON BELOW. SOME TRUCKS WILL EXPERIENCE AN INCREASED HEATER RESISTANCE OR REDUCTANT SYSTEM PERFORMANCE DUE TO AN OFFSET IN TEMPERATURE SENSOR OF DIESEL EMISSION REDUCTION FLUID TANK RESERVOIR, CAUSING THE MALFUNCTION INDICATOR LAMP TO ILLUMINATE. MODEL 2010-12 EXPRESS, SAVANA, 2011-12 SILVERADO HD, SIERRA HD. *PE