Buckle to Drive

Years 2016–19, 2021–27 Models 7 Factory citations 20

Also described as Safety belt assurance system, shifter interlockSafety belt assurance system, prevents shifting out of Park until the front seat belts are fastenedSeat belt assurance system, prevents shifting out of Park until the seat belts are fastenedBuckle to drive, non-configurable

Also documented for GMC

Documented applications

Colorado — Second generation (GMT31XX) (2015–2022)

2016–2019, 2021–2022 Factory-verified

fleet or government order types only (2018 guide); 2018 from GM's 2018 Colorado order guide (PDF); 2021 from the upfitter list GM files for 2021 and 2022

GM factory document — 2016 chevrolet canyon colorado electrical body builders manual service manual 2016 en us, p.13.
GM factory document — 2017 chevrolet canyon colorado electrical body builders manual service manual 2017 en us, p.17.
GM factory document — 2019 chevrolet 19 coloradocanyon body builder sm u 2018aug01 1, p.13.
GM factory document — 2022 chevrolet 22 canyon colorado electrical body builder sm en us 2021oct15, p.13.
GM factory document — 2018 chevrolet colorado order guide copy gm authority, p.24.

Colorado — Third generation (2023–2027)

2023–2027 Factory-verified

WT: O; LT, Trail Boss, Z71, ZR2: not offered

GM factory document — 2023 chevrolet 23colorado electrical body builder, p.13.
GM factory document — 2024 chevrolet 24colorado electrical body builder manual 18272478 2023oct09, p.14.
GM factory document — 2025 chevrolet colorado fleet order guide, p.31.
GM factory document — 2026 chevrolet colorado fleet order guide, p.36.
GM factory document — 2027 chevrolet colorado fleet order guide, p.35.

Cruze — first generation (2011–2016)

2016 Factory-verified

1SB, 1SD: O; order types FBC, FLS, FNR, FRC and FEF only

GM factory document — 2016 chevrolet cruze limited fleet order guide wayback, p.2.

Cruze — second generation (2016–2019)

2018–2019 Factory-verified

the 2018 guide names the driver and/or passenger belts, the 2019 guide the driver belt; 2018: sedan O: 1SB, 1SD, 1SH, 1SF; hatch O: 1SD, 1SF; 2019: sedan O: 1SB, 1SD, 1SF; hatch O: 1SB, 1SD, 1SF

GM factory document — 2018 chevrolet cruze order guide copy gm authority, p.45, p.53, p.87.
GM factory document — 2019 chevrolet cruze order guide june 1 2018 copy gm authority, p.32, p.38, p.70.

Malibu — ninth generation (2016–2025)

2025 Factory-verified

all trims: O; commercial fleet and government only; not available with T8Z or for fleet daily rental; the guide's wording omits the Settings switch T8Z has

GM factory document — 2025 chevrolet malibu fleet order guide, p.10.

Silverado 1500 — Fifth generation (2027)

2027 Factory-verified

GM factory document — 2027 chevrolet next generation silverado 1500 retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2027 chevrolet next generation silverado 1500 retail and fleet fleet order guide, p.41.

Silverado — T1XX (2019–2026)

2023–2026 Factory-verified

GM factory document — 2023 chevrolet 23 silverado 1500 electrical body builder sm en us 2022oct24, p.14.
GM factory document — 2024 chevrolet 24 silverado1500 electrical body builder 2023nov29, p.17.
GM factory document — 2025 chevrolet silverado 1500 retail and fleet fleet order guide rpo codes, p.1.
GM factory document — 2026 chevrolet silverado 1500 retail and fleet fleet order guide rpo codes, p.1.

This page aggregates every documented appearance of T4Z in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.