2003 GMC Sierra 1500 Service and Repair Manual

This factory service and repair manual for the 2003 GMC Sierra 1500 covers six trims, Base, Denali, SL, SLE, SLT and WT, in two-door standard cab and four-door extended cab pickup bodies. The engine choices are the flex-fuel or gasoline 325-cubic-inch 5.3L V8, the gasoline 294-cubic-inch 4.8L V8 and 364-cubic-inch 6.0L V8, and the 262-cubic-inch 4.3L V6, every one of them naturally aspirated with overhead valves. Specifications and torque values are given engine by engine.

Engines covered

• 5.3L V8 (325 cu in) — OHV, naturally aspirated, flex-fuel or gasoline
• 4.8L V8 (294 cu in) — OHV, naturally aspirated, gasoline
• 4.3L V6 (262 cu in) — OHV, naturally aspirated, gasoline
• 6.0L V8 (364 cu in) — OHV, naturally aspirated, gasoline

Body styles covered

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

Trims covered

• Base
• Denali
• SL
• SLE
• SLT
• WT

Known issues on the 2003 Sierra 1500. Eight recalls have been issued for this model year. Some trucks left the plant without a continuous urethane bead bonding the windshield to the body, so the glass might not stay in place in a crash. A hydro-boost housing was machined with an out-of-specification relief valve bore, which could fracture the valve O-ring and raise the pedal effort needed to slow the truck. Rear lap belt routing could ride up onto an occupant's abdomen instead of sitting low on the hips. Complaints number 573: 249 service brakes, 104 electrical system, 54 steering.