Trim group, Enclave Preferred

Years 2007, 2012–14, 2016–21, 2025–27 Models 8 Factory citations 15

Also described as Equipment group 1SDEquipment group, Sport TouringEquipment group 1SD, PreferredEquipment group 1SD, ConveniencePackage, option 04Trim group, Verano

Also documented for Cadillac Chevrolet GMC Pontiac

Documented applications

Enclave — C1XX (2018–2024)

2019–2021 Confirmed

only in: FWD; the entry model, replacing the base 1SV; dropped for 2022; 2019–2021: GM Authority

Enclave — VSS-S (2025–2027)

2025–2027 Factory-verified

Preferred: S; GM fleet model 4LB56; shown in the trim headings of the guides; GM Authority gives 1SD (4LB56) for the 2026 Preferred; NICB prints the series as Preferred

GM factory document — 2025 buick all new enclave fleet order guide, p.1.
GM factory document — 2026 buick enclave fleet order guide, p.1.
GM factory document — 2027 buick enclave fleet order guide, p.1.

Encore — Gamma II (2013–2022)

2013–2014, 2018 Factory-verified

2013–2014: Convenience (NICB: Convenience Group); 2018: Preferred II; not in the 2019 guide

GM factory document — 2013 buick encore fleet order guide wayback, p.1.
GM factory document — 2014 buick encore fleet order guide wayback, p.2.
GM factory document — 2018 buick encore order guide copy gm authority, p.1.

Encore GX — VSS-F (2020–2027)

2025–2026 Factory-verified

trim group heading of the Sport Touring columns (FWD and AWD)

GM factory document — 2025 buick encore gx fleet order guide, p.1.
GM factory document — 2026 buick encore gx fleet order guide, p.1.

Envision — D2XX, imported from China (2016–2020)

2017–2020 Factory-verified

front- and all-wheel drive (4XR26, 4XY26); the 2017 guide and GM Authority's 2017 page call it Convenience; the NICB manuals list Preferred from 2017; 2020: GM Authority's article on the 2020 Espresso Metallic paint

GM factory document — 2017 buick envision order guide copy gm authority, p.1.
GM factory document — 2018 buick envision order guide copy gm authority, p.1.
GM factory document — 2019 buick envision order guide copy gm authority, p.1.

LaCrosse — Epsilon II, 2nd gen (2010–2016)

2012 Confirmed

replaced the CX with PDD for 2012 (GM Authority 2012 RPO list); deleted for 2013, its content moved to 1SB (GM Authority 2013 changes)

Terraza — U-body / GMT201 (2005–2007)

2007 Factory-verified

GM factory document — 2007 buick terraza rpo code list, p.1.

Verano — Delta II (2012–2017)

2012, 2014, 2016 Factory-verified

2012: GM 2012 ordering guide (4PG69); 2014: GM 2014 fleet guide, Verano page (engine list, model 4PG69); 2016: page 1 model heading "1SV, 1SD, 1SG & 1SH"

GM factory document — 2016 buick verano fleet order guide wayback, p.1.
GM factory document — 2012 buick verano online ordering guide copy gm authority, p.1.
GM factory document — 2014 gm fleet car truck guide copy xr793, p.33.
2017 Single-source

2017 rests only on the NICB VIN manual (2017 p.42, Canada only); no GM list for 2017

This page aggregates every documented appearance of 1SD in the Buick reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.