Transmission, 8 speed automatic, electronically controlled, with overdrive, includes Driver Shift Control

Years 2025–27 Models 1 Factory citations 3

Also documented for Chevrolet

Documented applications

Terrain — Third generation (2025–2027)

2025–2027 Factory-verified

2025: S: Elevation AWD; not offered: Elevation FWD; 2026: S: Elevation AWD, AT4, Denali; not offered: Elevation FWD; 2027: S on all trims; the 2025 and 2026 guides pair it with the all-wheel-drive columns (the front-wheel-drive Elevation has MRQ); the 2027 guide marks it standard in all four columns

GM factory document — 2025 gmc next generation terrain fleet order guide, p.5.
GM factory document — 2026 gmc next generation terrain fleet order guide, p.8.
GM factory document — 2027 gmc terrain fleet order guide, p.8.

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