2003 GMC Sierra 2500 HD Service and Repair Manual

This factory service and repair manual for the 2003 GMC Sierra 2500 HD carries four trims, Base, SLE, SLT and WT, spread over a 2-door standard cab pickup, a 4-door crew cab pickup and a 4-door extended cab pickup. Buyers chose between a 6.6L turbocharged diesel V8 of 403 cubic inches, a 6.0L overhead-valve V8 of 364 cubic inches running gasoline or CNG, and an 8.1L gasoline V8 of 496 cubic inches. The manual keeps procedures, specifications, torque values, wiring diagrams and diagnostics separate for each of those three engines.

Engines covered

• 6.6L V8 (403 cu in) — OHV, turbocharged, diesel
• 6.0L V8 (364 cu in) — OHV, naturally aspirated, gasoline or CNG
• 8.1L V8 (496 cu in) — OHV, naturally aspirated, gasoline

Body styles covered

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

Trims covered

• Base
• SLE
• SLT
• WT

Known issues on the 2003 Sierra 2500 HD. Eight recalls are recorded federally. Some trucks left the plant without a continuous urethane bead bonding the windshield to the body, so the glass may not be retained in a crash. A brake hydro-boost housing was machined with an out-of-specification relief valve bore, allowing the valve seal to fracture and raising braking and steering effort. Second-row center lap belts could also sit high on the abdomen rather than low across the hips. Of 573 owner complaints, 249 concern service brakes, 104 the electrical system and 54 steering. Glass, brake and restraint procedures with their torque values are all here.