AT4 Premium Plus Package

Years 2018–19, 2021, 2025–27 Models 4 Factory citations 9

Query this via API →

Also described as High Elevation packageHD SLE gas preferred plus package

Documented applications

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

2021 Factory-verified

the 2021 guide names it as the package that brings AL9 and KA1 to the Elevation trim

GM factory document — 2021 gmc canyon fleet order guide wayback, p.1.

Sierra HD — K2XX (2015–2019)

2018–2019 Factory-verified

the SLE preferred package content plus spray-on bedliner (CGN) and LPO all-weather floor liner (RIA), and trailering mirrors (DPN) on Crew Cab; not with the Duramax diesel (L5P); the 2018 guide prints HD SLE Preferred Plus Package; 2019 marks: Sierra, SLT: not offered; SLE: O; 2018: GM's 2018 Sierra 2500HD order guide

GM factory document — 2019 gmc sierra 2500hd fleet order guide wayback, p.1.
GM factory document — 2018 gmc sierra 2500hd order guide copy gm authority, p.14.

Yukon — T1XX (2021–2027)

2025–2027 Factory-verified

2027: AT4: O; includes RGM, NHT, Z6E, ZM1, B3L

GM factory document — 2025 gmc new yukon denali fleet order guide, p.21.
GM factory document — 2026 gmc yukon denali fleet order guide, p.22.
GM factory document — 2027 gmc yukon fleet order guide, p.21.

Yukon XL — T1XX (2021–2027)

2025–2027 Factory-verified

2027: AT4: O; includes RGM, NHT, Z6E, ZM1, B3L

GM factory document — 2025 gmc new yukon xl denali fleet order guide, p.21.
GM factory document — 2026 gmc yukon xl denali fleet order guide, p.22.
GM factory document — 2027 gmc yukon xl fleet order guide, p.21.

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