The all new Sierra HD launched last year and GMC is already making changes. What’s new? What’s changed? Take a look at our 2021 Sierra HD guide.

2021 GMC Sierra HD What’s New Rundown

Here’s the highlights of what GMC has changed in this new model year

  • Multi Pro Tailgate now standard on SLE Trims
  • The 40/20/40 split front seat has been discontinued
  • Bed View Camera will show in rear view mirror
  • No increase in power for both gas and Duramax diesel engine options
  • Wireless Android Auto and Apple CarPlay Projection
  • Assist steps, power-retractable, stainless steel accents, includes LED lights
  • Denali Black Diamond Edition

2021 Sierra HD Deletions

When GMC tweaks models from year to year some colors, features, and options are discontinued. For 2021, here’s the features no longer avalaible on the Sierra HD.

  • (A52) Front 40/20/40 split-bench seat
  • (GJI) Dark Sky Metallic exterior paint
  • (GPJ) Red Quartz Tintcoat exterior paint
  • (QT3) Manual tailgate function with lift assist
  • (PYR) Wheels, 18″ (45.7 cm) 6-spoke machined aluminum with high gloss Black accents Extended
  • (PDT) SLT Premium Plus Package
  • (PDW) Texas Edition SLT Premium Plus Package
  • (MCY) Single USB Port

2021 Sierra HD New Features

Most features or colors that have been discontinued are replaced by updated colors or features. Here’s what’s totally new in the Sierra HD for 2021.

  • (GB8) Ebony Twilight Metallic exterior paint
  • (GSK) Cayenne Red Tintcoat exterior paint
  • (GED) Hunter Metallic exterior paint
  • (RGE) Safety Essentials Package – includes (UEU) Forward Collision Alert, (UHY) Automatic Emergency Braking, (K34) Cruise Control, (UK3) Steering wheel audio controls and (UDD) Driver Information Center
  • (PDB) SLT Premium Package – includes (PCY) SLT Convenience Package, (PDY) SLT Preferred Package, (PQB) Driver Alert Package I, (BVQ) 6″ rectangular, cab length Chrome assist steps (Crew Cab models only), (VXH) 6″ Chrome rectangular tubular assist step, LPO (Double Cab models only) and (CGN) spray-on bedliner. No substitutions to the above content.
  • (PDC) Texas Edition SLT Premium Package –  includes (PCY) SLT Convenience Package, (PDY) SLT Preferred Package, (PQB) Driver Alert Package I, (BVQ) 6″ rectangular, cab length Chrome assist steps (Crew Cab models only), (VXH) 6″ Chrome rectangular tubular assist step, LPO (Double Cab models only), (CGN) spray-on bedliner and Texas Edition badging. No substitutions to the above content.
  • (PDG) AT4 Premium Plus Package – includes (PDO) AT4 Preferred Package, (PQB) Driver Alert Package I, (PDJ) Driver Alert II, (PYU) 20″ (50.8 cm) machined aluminum wheels with high gloss Black accents, (CF5) power sunroof, (CWM) Technology Package and (VXW) AT4 high clearance step, LPO
  • (JSE) Denali Black Diamond Edition – includes (TRO) Auxiliary Trailer Camera, (PDV) MultiPro Audio System by Kicker, (BKF) front floor liners with removable carpet insert, (BKE) rear floor liners with removable carpet insert, (PTT) trailer tire pressure monitor sensors, (BRS) power-retractable assist steps with LED perimeter lighting and (RTJ) 20″ (50.8 cm) high gloss Black painted aluminum wheels
  • (RFX) X31 Off-Road and Protection Package – includes (X31) Off-Road suspension with Twin-tube Rancho shocks, (JHD) Hill Descent Control and (NZZ) skid plates (transfer case and oil pan), (CGN) spray-on bedliner, (RIA) All-weather floor liners, LPO and X31 badge (replaces “4X4” badge on bed)
  • (BKF) Premium front floor liners with removable carpet inserts
  • (BKE) Premium rear floor liners with removable carpet inserts
  • (DRC) Mirror, inside rearview auto dimming with partial video display
  • (UVO) Bed View Camera, camera in the CHMSL to show a view of the cargo bed, display located in rearview mirror
  • (VXW) LPO, AT4 high clearance step
  • (BRS) Assist steps, power-retractable, stainless steel accents, includes LED lights
  • (DP6) Mirror caps, high gloss Black on AT4
  • (QG3) LT275/70R18, mud-terrain, blackwall tires
  • (PXD) Wheels, 18″ (45.7 cm) machined aluminum wheel with Dark Grey metallic accents
  • (RTJ) Wheels, 20″ (50.8 cm) high gloss Black painted aluminum
  • (RW9) LPO, Bedside Storage, right hand and left hand side
  • (5VI) LPO, Tie-Downs, (4)
  • (Q7Q) Wheels, 20″ Black Transit wheels for 20″ LPO wheels
  • (FHS) E85 FlexFuel capable on gasoline engine
  • (SKW) LPO, 20″ (50.8 cm) multi-dimensional Chrome aluminum wheels
  • (SKX) LPO, 20″ (50.8 cm) high gloss Black aluminum wheels with machined accents

2021 GMC Sierra HD Changes

Every model year GMC makes small changes to certain options, features, and package groups. Here’s what’s changed in the 2021 Sierra HD from last year.

  • PCQ) SLE Convenience Package no longer includes (QT5) EZ Lift power lock and release tailgate
  • (PDY) SLT Preferred Package now includes (UVN) Bed View Camera and (UVS) HD Surround Vision with Two Trailer View Camera Provisions
  • (PDO) AT4 Preferred Package now includes (UVN) Bed View Camera and (UVS) HD Surround Vision with Two Trailer View Camera Provisions
  • (AE7) front 40/20/40 split-bench seat with upper covered armrest storage is standard on 1SA
  • (U2K) SiriusXM is standard on 3SA and available on 1SA
  • (Q7R) 20″ wheels with new finish, machined aluminum wheel with bright Silver accents
  • (PYU) 20″ wheels with new finish, machined aluminum with high gloss Black accents
  • (CWM) Technology Package, no longer includes (UVN) Bed View Camera or (UVS) HD Surround Vision
  • (BG9) rubberized-vinyl floor covering is standard on 1SA
  • (B30) color-keyed carpeting is available on 1SA
  • (UVN) Bed View Camera is now included in (PDY) SLT Preferred Package and (PDO) AT4 Preferred Package
  • (UVS) HD Surround Vision with Two Trailer View Camera Provisions is now included in
  • (PDY) SLT Preferred Package and (PDO) AT4 Preferred Package
  • (QK1) standard tailgate is now available on 3SA
  • (QK2) GMC MultiPro Tailgate is now standard on 3SA
  • (CMT) Gooseneck / 5th Wheel Package is not available on Denali you now order free flow option (Z6A) Gooseneck / 5th Wheel Prep Package on Denali Trim only
  • (ZL6) ProGrade Trailering System no longer includes (U2K) Sirius XM and (QT5) EZ Lift and power lock and release tailgate
  • (A50) Bucket seats are not available on 3SA trim