Transmission, 8 speed automatic, 8L90

Years 2016–18 Models 1 Factory citations 1

Documented applications

CT6 — Omega (2016–2020)

2016–2017 Single-source

with the 3.0L twin turbo LGW, as GM Authority's LGW engine page gives it; no factory list in the archive shows it; GM Authority's LGW page also gives it for 2019, but the 2019 CT6 order guide prints MHS for every 2019 trim including the 3.0L cars, so 2019 is dropped
2018 Factory-verified

2018: Luxury, Premium Luxury, Platinum 3.0L twin turbo AWD: S, with LGW; from the 2018 CT6 order guide (a GM document)

GM factory document — 2018 cadillac ct6 order guide copy gm authority, p.61.

This page aggregates every documented appearance of M5X in the Cadillac reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.