Trim group, AT4

Years 2008–09, 2014–27 Models 10 Factory citations 36

Also described as Package, SLT option 2Trim group, SLT-2Trim group, Acadia AT4, all-wheel driveTrim group, SLT option 2Equipment group 4SB, SLT DieselTrim group, Terrain AT4, all-wheel drive

Documented applications

Acadia — first generation, Lambda (2007–2017)

2008–2009, 2014–2016 Factory-verified

2014–2016 guides: equipment group SLT-2.

GM factory document — 2008 gmc acadia 2wd rpo code list, p.1.
GM factory document — 2009 gmc acadia 2wd rpo code list, p.1.
GM factory document — 2014 gmc acadia fleet order guide wayback, p.1.
GM factory document — 2015 gmc acadia fleet order guide wayback, p.1.
GM factory document — 2016 gmc acadia fleet order guide wayback, p.1.

Acadia — Second generation (C1XX) (2017–2023)

2017–2019 Factory-verified

the 2020 and 2021 meaning of 4SB is the AT4 (next row)

GM factory document — 2017 gmc acadia order guide copy gm authority, p.1, p.29.
GM factory document — 2018 gmc acadia order guide copy gm authority, p.1, p.37.
GM factory document — 2019 gmc acadia order guide copy gm authority, p.1, p.39.
2020–2021 Single-source

only in: AWD (GM Authority lists the AT4 as an AWD model); GM Authority's 2020 changes page says the SLT-2 (4SB) became the AT4; the 2017–2019 meaning is the SLT-2 (row above); 2020: GM Authority 2020 Acadia page; 2021: GM Authority 2021 Acadia page

Acadia — Third generation (2024–2027)

2025–2027 Factory-verified

AT4: S; GM fleet model TLE56; shown in the trim headings of the guides; NICB prints the series as AT4 AWD (2024 and 2026)

GM factory document — 2025 gmc acadia fleet order guide, p.1.
GM factory document — 2026 gmc acadia fleet order guide, p.1.
GM factory document — 2027 gmc acadia fleet order guide, p.1.

Sierra 1500 — Next-Generation (2027)

2027 Factory-verified

4WD Crew Cab; Crew Cab Standard Box models are late availability

GM factory document — 2027 gmc next generation sierra 1500 retail and fleet fleet order guide, p.1.

Sierra HD — T1XX (2020–2027)

2025–2027 Factory-verified

only in: 2500 HD and 3500 HD pickup; NICB 2026 lists the AT4 as a 2500 and 3500 4WD series

GM factory document — 2025 gmc sierra 2500 hd retail and fleet fleet order guide, p.1.
GM factory document — 2026 gmc sierra 2500 hd retail and fleet fleet order guide, p.1.
GM factory document — 2027 gmc sierra 2500 hd retail and fleet fleet order guide, p.1.

Sierra — T1XX (2019–2026)

2019–2020, 2022–2026 Factory-verified

the 2025 and 2026 guides head this column AT4

GM factory document — 2019 gmc 19 sierra 1500 body builder feb 20, p.9.
GM factory document — 2020 gmc 20 sierra 1500 electrical body buil 1, p.9.
GM factory document — 2022 gmc 22 sierra 1500 new electrical body builder sm en us 2022jul20, p.10.
GM factory document — 2023 gmc 23 sierra 1500 electrical body builder sm en us 2022oct12, p.9.
GM factory document — 2024 gmc 24 sierra 1500 sm electrical body builder esid 23dec12, p.10.
GM factory document — 2025 gmc my25 sierra 1500 electrical bbm, p.8.
GM factory document — 2025 gmc sierra 1500 retail and fleet fleet order guide, p.168, p.169.
GM factory document — 2026 gmc sierra 1500 retail and fleet fleet order guide, p.85, p.86.

Terrain — Second generation (D2XX) (2018–2024)

2019 Factory-verified

FWD and AWD models (TXM26, TXC26); LH7 diesel; dropped for 2020 (GM Authority 2020 changes page)

GM factory document — 2019 gmc terrain order guide copy gm authority, p.1, p.47.

Terrain — Third generation (2025–2027)

2026–2027 Factory-verified

AT4: S; GM fleet model TPD26; shown in the trim headings of the 2026 and 2027 guides; NICB prints the series as AT4 AWD (2026, VIN positions 5 and 6 LY)

GM factory document — 2026 gmc next generation terrain fleet order guide, p.1.
GM factory document — 2027 gmc terrain fleet order guide, p.1.

Yukon — T1XX (2021–2027)

2022–2023, 2025–2027 Factory-verified

the body-builder lists name it SLT option 2

GM factory document — 2022 gmc 22 yukon yukon xl electrical body builder sm u 2021oct13, p.9.
GM factory document — 2023 gmc 23 yukon yukon xl electrical body builder sm en us 092822, p.9.
GM factory document — 2025 gmc new yukon denali fleet order guide, p.1.
GM factory document — 2026 gmc yukon denali fleet order guide, p.1.
GM factory document — 2027 gmc yukon fleet order guide, p.1.

Yukon XL — T1XX (2021–2027)

2022–2023, 2025–2027 Factory-verified

the body-builder lists name it SLT option 2

GM factory document — 2022 gmc 22 yukon yukon xl electrical body builder sm u 2021oct13, p.9.
GM factory document — 2023 gmc 23 yukon yukon xl electrical body builder sm en us 092822, p.9.
GM factory document — 2025 gmc new yukon xl denali fleet order guide, p.1.
GM factory document — 2026 gmc yukon xl denali fleet order guide, p.1.
GM factory document — 2027 gmc yukon xl fleet order guide, p.1.

This page aggregates every documented appearance of 4SB in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.