2021 GMC Sierra HD Changes, Updates, New Features

The 2021 Sierra HD receives quite a few updates and changes, including new colors, new wheel availability, new standard features, and new packaging contents.

Exterior

Deletion of two exterior color options
- Dark Sky Metallic
- Red Quartz Tintcoat
Addition of three exterior color options
- Ebony Twilight Metallic
- Cayenne Red Tintcoat
- Hunter Metallic
Deletion of 18-inch (45.7 cm) 6-spoke machined aluminum extended wheels with high gloss Black accents
Addition of AT4 high clearance step (LPO-level item)
Addition of power-retractable Assist steps with stainless steel accents
- Includes LED lights
Addition of new, high gloss Black mirror caps for AT4 models
Addition of LT275/70R18, mud-terrain, blackwall tires (QG3)
- For 2500HD models only, not available for 3500HD models
Addition of 18-inch (45.7 cm) machined aluminum wheel with Dark Grey metallic accents (PXD)
Addition of 20-inch (50.8 cm) high gloss Black painted aluminum wheels (RTJ)
Addition of Bedside Storage, right hand and left hand side
Addition of Tie-Downs option – includes 4
Addition of 20-inch Transit wheels for 20-inch LPO-level wheels
Addition of 20-inch machined aluminum wheel wheels with new finish and bright Silver accents
Addition of 20-inch wheels with new finish, machined aluminum with high gloss Black accents (SKX)
- Only available for Denali and AT4 models
- LPO-level item
Addition of 20-inch (50.8 cm) multi-dimensional Chrome aluminum wheels (SKW)
- Only available for Denali models
- LPO-level item
GMC MultiPro Tailgate is now standard on SLE models
- Standard tailgate (QK1) is now available on SLE models, remains standard on base models, and is no longer available for SLT, AT4, or Denali models
- For the 2020 model year, the QT3 tailgate – manual gate function with lift assist – was standard on base and SLE models
Deletion of manual tailgate function with lift assist

Interior

Deletion of front 40/20/40 split-bench seat
Deletion of single USB Port
Addition of Premium floor liners with removable carpet inserts
- Front and rear
Addition of inside rearview auto dimming mirror with partial video display
Addition of Bed View Camera in the CHMSL to show a view of the cargo bed
- Display located in rearview mirror
Front 40/20/40 split-bench seat with upper covered armrest storage is now standard on base (1SA) Sierra HD models
- For the 2020 model year, the 40/20/40 split-bench seat was standard
SiriusXM is now standard on SLE models and available on base models
- For the 2020 model year, SiriusXM was only standard on SLT, AT4, and Denali models

Mechanical

Gasoline engine options are now E85 FlexFuel capable
Gooseneck / 5th Wheel Package is not available on Denali models
- Gooseneck / 5th Wheel Prep Package is now a free flow option
- Change applies to Denali models only
ProGrade Trailering System no longer includes:
- EZ Lift and power lock and release tailgate
- Still includes:
  - Hitch Guidance with Hitch View
  - In-vehicle Trailering App
  - 8-inch diagonal Premium GMC Infotainment System
  - HD Rear Vision Camera
  - USB Ports (Instrument Panel with bench seat)
  - SiriusXM with 360L
  - HD Radio
- Only available for SLE models

Packaging

Addition of the AT4 Premium Plus Package, which is exclusive to AT4 models and includes:
- Driver Alert Package I:
  - Front and Rear Park Assist
  - Lane Change Alert with Side Blind Zone Alert
  - Rear Cross Traffic Alert
  - Perimeter Lighting
- Driver Alert II:
- Technology Package:
  - Rear Camera Mirror
  - Multicolor 15-inch Diagonal Head-Up Display
- 20-inch (50.8 cm) machined aluminum wheels with high gloss Black accents (PYU)
  - Can be upgraded to:
    - 20-inch High gloss Black painted wheels (S6L)
      - (LPO-level item)
    - 20-inch high gloss Black aluminum wheels with machined accents (SKX)
      - (LPO-level item)
- Power sunroof
- AT4 high clearance step (LPO-level item)
  - AT4 high clearance step can be substituted with Black Sport Step (LPO-level item), but no other assist steps are available
Addition of Denali Black Diamond Edition, which is exclusive to Denali models and includes:
- Auxiliary Trailer Camera
- MultiPro Audio System by Kicker
- Premium front and rear floor liners with removable carpet insert
- Trailer tire pressure monitor sensors
- Power-retractable assist steps with LED perimeter lighting
- 2-inch (50.8 cm) high gloss Black painted aluminum wheels (RTJ)
- Requires:
  - 4WD model configuration
  - Ebony Twilight Metallic exterior color
  - 6.6-liter Duramax Turbo-Diesel L5P V8 engine
  - Denali Ultimate Package
    - Technology Package
    - Sunroof
  - Not available with any LPO wheels
Addition of the X31 Off-Road and Protection Package, which is available on SLE and SLT models and includes:
- Off-Road suspension with Twin-tube Rancho shocks
- Hill Descent Control
- Skid plates (transfer case and oil pan)
- Spray-on bedliner
- All-weather floor liners (LPO-level item)
- X31 badge (replaces “4X4” badge on bed)
- SLE models include:
  - 18-inch machined aluminum wheel with Dark Grey metallic accents (PXD) with LT275/70R18E all-terrain, blackwall tires
    - Wheels and tires may be upgraded to 20-inch machined aluminum wheel (Q7R) with bright Silver accents and LT275/65R20 all-terrain, blackwall tires
  - Requires Crew Cab or Double Cab 4WD model
  - Not available with pickup bed delete
- SLT models include:
  - 20-inch machined aluminum wheel with bright Silver accents (Q7R) and LT275/65R20 all-terrain, blackwall tires
  - Requires a 4WD model
  - Not available with pickup bed delete
Addition of 1SA Safety Confidence Package, which is available on base Sierra HD models and includes:
- Forward Collision Alert
- Automatic Emergency Braking
- Cruise Control
- Steering wheel audio controls
- Driver Information Center
- Not available with pickup bed delete
Technology Package no longer includes Bed View Camera or HD Surround Vision
New RPO code designation for SLT Premium Plus Package (PDB), which includes:
- SLT Convenience Package:
  - Bucket seats with center console
  - Ventilated front seats
  - Rear sliding power window
  - Universal Home Remote
  - USB Ports (Inside Console with bucket seats)
  - 2 USB ports with auxiliary input
  - Roof Marker Lamps
  - Crew Cab models also include rear heated seats
- SLT Preferred Package:
  - 8-inch diagonal Premium GMC Infotainment with navigation
  - Bose Premium Audio System
  - Wireless Charging
- Driver Alert Package I:
  - Front and Rear Park Assist
  - Lane Change Alert with Side Blind Zone Alert
  - Rear Cross Traffic Alert
  - For SLE models:
    - Includes Perimeter Lighting
    - Not available with pickup bed delete
    - Requires trailer mirrors
    - Requires SLE Convenience Package:
      - Dual climate control
      - 10-way power driver seat including power lumbar
      - Heated driver and passenger seats,
      - Heated steering wheel
      - Manual tilt/telescoping steering column
      - Rear-window defogger
      - Keyless Open and Start
      - Steering column lock
      - Remote Start
      - Content theft alarm
      - Front 40/20/40 split-bench with underseat storage on Crew Cab and Double Cab models
      - 2 charge-only USB ports for second row
      - Cargo bed LED lighting
      - Rear auxiliary 12-volt power outlet
      - Fog lights
      - Roof Marker Lamps
      - Rear wheelhouse liners
      - Included with SLE Value Package:
        
        Available for Crew Cab and Double Cab models
        
        Includes SLE Convenience package and (CGN) spray-on bedliner
      - Not available with:
        
        Remote Start Package
        
        Pickup bed delete
      - Note: Roof Marker Lamps are not available with vehicles that need to meet California state emissions requirements
  - For SLT models:
    - Includes Perimeter Lighting
    - Included with SLT Premium Package or Texas Edition SLT Premium Package
    - Not available with (ZW9) pickup bed delete
  - For AT4 models:
    - Includes Perimeter Lighting
    - Included with AT4 Premium Plus Package
- 6-inch rectangular, cab length Chrome assist steps
  - Available for Crew Cab models only
- 6-inch Chrome rectangular tubular assist step (LPO-level item)
  - Available for Double Cab models only)
  - Spray-on bedliner
  - No substitutions to the above content may be made
  - Not available with pickup bed delete or Texas SLT Premium Package
    - For the 2020 model year, the package included
New RPO code designation for Texas Edition SLT Premium Plus Package, which includes:
- - SLT Convenience Package
  - SLT Preferred Package
  - Driver Alert Package I
  - 6-inch rectangular, cab length Chrome assist steps
    - (Crew Cab models only)
  - 6-inch Chrome rectangular tubular assist step, LPO (Double Cab models only)
  - Spray-on bedliner
  - Texas Edition badging
  - No substitutions may be made to the above content
  - Not available with pickup bed delete or SLT Premium Package
  - Only available for dealers located in:
    - Arkansas
    - Louisiana
    - New Mexico
    - Oklahoma
    - Texas
SLE Convenience Package no longer includes EZ Lift power lock and release tailgate, still includes:
- Dual climate control
- 10-way power driver seat including power lumbar
- Heated driver and passenger seats
- Heated steering wheel
- Manual tilt/telescoping steering column
- Rear-window defogger
- Keyless Open and Start
- Steering column lock
- Remote Start
- Content theft alarm
- Front 40/20/40 split-bench with underseat storage
  - On Crew Cab and Double Cab models
- 2 charge-only USB ports for second row
- Cargo bed LED lighting
- Rear auxiliary 12-volt power outlet
- Fog lights
- Roof Marker Lamps
- Rear wheelhouse liners
- Included with SLE Value Package, which also includes:
  - Spray-on bedliner
  - Only available for Crew Cab and Denali Cab models
- Not available with:
  - Remote Start Package
  - Pickup bed delete
- Note: Roof Marker Lamps are not available with vehicles that need to meet California state emissions requirements
SLT Preferred Package now includes:
- Bed View Camera
- HD Surround Vision with Two Trailer View Camera Provisions
- Also includes:
  - 8-inch diagonal Premium GMC Infotainment with navigation
  - Bose Premium Audio System
  - Wireless Charging
  - Requires SLT Convenience Package
  - Included with SLT Premium Package or Texas Edition SLT Premium Package
AT4 Preferred Package now includes:
- Bed View Camera
- HD Surround Vision with Two Trailer View Camera Provisions
- Also includes:
  - Universal Home Remote
  - Rear sliding power window
  - 8-inch diagonal Premium GMC Infotainment with navigation
  - Bose Premium Audio System
  - Roof Marker Lamps
  - Wireless Charging
  - Included with AT4 Premium Package
  - Note: Roof Marker Lamps are not available with vehicles that need to meet California state emissions requirements