J21 ✓ Factory-verified

GMC · Regular Production Option

Engineering year, 2021

Years 2021–22 Models 2 Factory citations 2

Query this via API →

Also documented for Chevrolet

Documented applications

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

• 2021 ✓ Factory-verified internal

  ; 2021 from the upfitter list GM files for 2021 and 2022; shown only in the shared Colorado/Canyon upfitter lists

  ⛭ GM factory document — 2022 chevrolet 22 canyon colorado electrical body builder sm en us 2021oct15, p.11.

Sierra — T1XX (2019–2026) →

• 2022 ✓ Factory-verified internal
  ⛭ GM factory document — 2022 gmc 22 sierra 1500 new electrical body builder sm en us 2022jul20, p.12.

This page aggregates every documented appearance of J21 in the GMC reference. Confidence and citations are shown per application — the same code can be better documented in one year than another.