- 2025–2027 Factory-verified
only in: 2500 HD, 3500 HD, 3500 HD chassis cab; same wording as MGM; the 2026 list omits "Allison"
MKM Factory-verified
Also documented for GMC
Documented applications
This page aggregates every documented appearance of MKM in the Chevrolet reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.