2023 GMC Sierra Service and Repair Manual
This factory service and repair manual for the 2023 GMC Sierra takes in a widened trim list of AT4, Denali, Denali Ultimate and SLE, still built on the four-door crew cab and two-door standard cab pickup bodies. The 325-cubic-inch 5.3L V8 and the 376-cubic-inch 6.2L V8 carry over, both gasoline, naturally aspirated and overhead-valve. Specifications, torque values, wiring diagrams and diagnostic procedures are set out system by system across the whole range.
Engines covered
- 5.3L V8 (325 cu in) — OHV, naturally aspirated, gasoline
- 6.2L V8 (376 cu in) — OHV, naturally aspirated, gasoline
Body styles covered
- 4-door crew cab pickup
- 2-door standard cab pickup
Trims covered
- AT4
- Denali
- Denali Ultimate
- SLE
Known issues on the 2023 Sierra. Three recalls stand on the federal record. The 6.2L V8 is subject to one for connecting rod and crankshaft defects that can damage the engine badly enough to stop it. Another concerns daytime running lamps that do not switch off when they should, throwing glare at oncoming traffic. The third covers a brake fluid low-level warning lamp that may not meet the federal standard, so a truck can be driven with the fluid down and braking already degraded. Complaints number 455: 145 engine, 87 power train, 68 structure.
