2020 GMC Sierra 1500 Service and Repair Manual

This factory service and repair manual for the 2020 GMC Sierra 1500 has the broadest engine list of the run: a 183-cubic-inch 3.0L turbocharged inline-six diesel with double overhead cams, a turbocharged 166-cubic-inch 2.7L inline-four, and the naturally aspirated overhead-valve 325-cubic-inch 5.3L V8, 376-cubic-inch 6.2L V8 and 262-cubic-inch 4.3L V6. Six trims and three cab lengths are covered, and the diesel's fuel, emissions and diagnostic material stands on its own.

Engines covered

• 5.3L V8 (325 cu in) — OHV, naturally aspirated, gasoline or flex-fuel
• 6.2L V8 (376 cu in) — OHV, naturally aspirated, gasoline
• 3.0L inline-six (183 cu in) — DOHC, turbocharged, diesel
• 4.3L V6 (262 cu in) — OHV, naturally aspirated, gasoline
• 2.7L inline-four (166 cu in) — DOHC, turbocharged, gasoline

Body styles covered

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

Trims covered

• Base
• AT4
• Denali
• Elevation
• SLE
• SLT

Known issues on the 2020 Sierra 1500. Eight recalls are on the federal record. Some fuel pumps were assembled without a pressure regulator, so fuel system pressure could climb until the pump cracked and leaked. A roof-rail air bag inflator diffuser that was not crimped properly could separate during deployment and blunt the bag's performance. Battery positive cable rings with too much glue could make an intermittent alternator connection and stall the engine. Complaints total 456, led by the engine at 154, the power train at 88 and the electrical system at 50.