2012 GMC Sierra 3500 HD Service and Repair Manual

This factory service and repair manual for the 2012 GMC Sierra 3500 HD treats a one-ton platform sold both as a finished pickup and as a cab and chassis — five configurations in all, in two- and four-door forms. Power comes from the 403-cubic-inch 6.6L turbocharged diesel V8 or the 364-cubic-inch 6.0L naturally aspirated V8 running gasoline or flex-fuel, both overhead-valve, and the trim range covers Denali, SLE, SLT and WT. Specifications and torque values are kept apart for each engine.

Engines covered

• 6.6L V8 (403 cu in) — OHV, turbocharged, diesel
• 6.0L V8 (364 cu in) — OHV, naturally aspirated, gasoline or flex-fuel

Body styles covered

• 4-door crew cab pickup
• 4-door cab & chassis
• 4-door extended cab pickup
• 2-door cab & chassis
• 2-door standard cab pickup

Trims covered

• Denali
• SLE
• SLT
• WT

Known issues on the 2012 Sierra 3500 HD. Four recalls are on the federal record here. Two describe passenger frontal air bag inflators that can burst during deployment and send metal fragments through the cabin. A third applies to trucks with dual fuel tanks, where a sticking low-level sensor allows the rear tank to overfill the front, expanding it into the driveshaft and opening a leak. The fourth covers a fire extinguisher that may clog. Thirty-eight complaints lead with the electrical system, then air bags and power train — circuits, restraints and driveline all appear in these diagnostics.