2004 Chevy Silverado Service 4WD
C0306, C0321, C0327 codes. NP246, Decoder Motor, 4WD selector switch. GMC Sierra Eric O. with South Main Auto had a great video ( • Chevy / GMC Truck: Service 4WD Message & N... ) that pointed me in the right direction. His content is very thorough, and he's pretty funny. MAY03LT has a video ( • 03-06 Silverado/Sierra Service 4 Wheel Dri... ) that also helped me figure out how some of these systems functioned and allowed me to confidently troubleshoot some of the issues. I thank both of these guys for leading the way. #1999-2006 Chevy GMC #1999-2006 Silverado Sierra #NP246 Transfer Case codes #C0306 #C0321 #C0327 #Service 4WD #Service Brake System
