2021 GMC SIERRA 3500HD AT4

• StabiliTrak, stability control system with Proactive Roll Avoidance and traction control includes electronic trailer sway control and hill start assist
• Hill Descent Control
• Airbags, Dual-stage frontal airbags for driver and front outboard passenger; Seat-mounted side-impact airbags for driver and front outboard passenger; Head-curtain airbags for front and rear outboard seating positions; Includes front outboard Passenger Sensing System for frontal outboard passenger airbag (Always use seat belts and child restraints. Children are safer when properly secured in a rear seat in the appropriate child restraint. See the Owner's Manual for more information.)
• Hitch Guidance dynamic single line to aid in truck trailer alignment for hitching
• Rear Seat Reminder
• Teen Driver a configurable feature that lets you activate customizable vehicle settings associated with a key fob, to help encourage safe driving behavior. It can limit certain available vehicle features, and it prevents certain safety systems from being turned off. An in-vehicle report card gives you information on driving habits and helps you to continue to coach your new driver

PACKAGE (2)

• X31 Off-Road Package includes (JHD) Hill Descent Control, (NZZ) skid plates, Off-Road suspension and Twin-tube Rancho shocks
• ProGrade Trailering System includes (PZ8) Hitch Guidance with Hitch View and (U1D) In-vehicle Trailering App

MECHANICAL (20)

• Rear axle, 3.73 ratio (Requires (L8T) 6.6L V8 gas engine.)
• GVWR, 11,500 lbs. (5216 kg) with single rear wheels (Included and only available with model TK30943 model and (L8T) 6.6L V8 gas engine. Requires single rear wheels.)
• Air filter, heavy-duty
• Air filtration monitoring
• Transfer case, two-speed active electronic Autotrac with push button control
• Auto-locking rear differential
• Four wheel drive
• Cooling, external engine oil cooler
• Cooling, auxiliary external transmission oil cooler
• Battery, heavy-duty 720 cold-cranking amps/80 Amp-hr maintenance-free with rundown protection and retained accessory power (Included and only available with (L8T) 6.6L V8 gas engine.)
• Alternator, 170 amps (Requires (L8T) 6.6L V8 gas engine.)
• Trailer brake controller, integrated
• Recovery hooks, Red
• Frame, fully-boxed, hydroformed front section and a fully-boxed stamped rear section
• Skid Plates protect the oil pan, front axle and transfer case
• Suspension, Off-Road includes twin-tube shocks
• Steering, Digital Variable Steering Assist This system automatically adjusts steering based on speed, road conditions, and other inputs to reduce driver effort and fatigue
• Brakes, 4-wheel antilock, 4-wheel disc with DURALIFE rotors
• Brake lining wear indicator
• Capless Fuel Fill (Requires (L8T) 6.6L gas V8 engine.)

EXTERIOR (23)

• Tire, spare LT275/70R18 all-terrain, blackwall
• Single Rear Wheels
• Tire carrier lock keyed cylinder lock that utilizes same key as ignition and door
• Bumper, front, body-color lower
• Bumper, rear body-color with bumper CornerSteps
• CornerStep, rear bumper
• Bed Step, Black integrated on forward portion of bed on driver and passenger side
• Moldings, beltline, Black
• Wheelhouse liners, rear
• Bed Liner, Spray-on Pickup bedliner with GMC logo (does not include spray-on liner on tailgate due to Black composite inner panel) (AT4 logo replaces GMC logo. Not available with any Ship Thrus EXCEPT (VSH), (VTV), (TCH) or (TCE).)
• Cargo tie downs (12), fixed, rated at 500 lbs per corner
• Grille, Painted Black surround with high gloss Black mesh and Black chrome inserts
• Fog lamps, LED
• Taillamps, LED signature taillight with LED stop and reverse light
• Lamps, cargo area, cab mounted integrated with center high mount stop lamp, with switch in bank on left side of steering wheel
• LED Cargo Area Lighting located in cargo bed activated with switch on center switch bank or key fob
• Mirrors, outside power-adjustable vertical trailering with heated and auto-dimming upper glass, (driver and passenger) lower convex mirrors, turn signal indicators, puddle lamps, perimeter lighting, auxiliary lighting, power folding/extending (extends 3.31" [84.25mm])
• Mirror caps, high gloss Black
• Glass, deep-tinted
• Door handles, body-color
• Tailgate, GMC MultiPro Tailgate with six functional load/access features
• Tailgate and bed rail protection caps, top
• Tailgate, gate function manual with EZ Lift includes power lock and release, includes hitch area light

ENTERTAINMENT (2)

• HD Radio
• Audio system feature, 6-speaker system

INTERIOR (29)

• 4G LTE Wi-Fi Hotspot capable (Terms and limitations apply. See onstar.com or dealer for details.)
• Seat adjuster, driver 10-way power including lumbar
• Seat adjuster, passenger 10-way power including lumbar
• Seat, Up-level Rear with Storage Package, 60/40 folding bench for Crew Cab models includes full-length bench seat, seatback storage on left and right side, center fold out armrest with 2 cupholders, full cab width underseat storage, (includes child seat top tether anchor)
• Seats, heated second row outboard seats
• Driver memory, recalls driver "presets" for power driver seat and outside mirrors
• Center Console, floor-mounted with cup holders, cell phone storage, power cord management, hanging file folder capability
• Floor covering, color-keyed carpeting
• Steering wheel, leather-wrapped
• Steering wheel, heated
• Steering column, manual Tilt-Wheel and telescoping
• Steering wheel audio controls
• Instrument cluster, 6-gauge cluster featuring speedometer, fuel level, engine temperature, tachometer, voltage and oil pressure
• Driver Information Center, 4.2" diagonal color display includes driver personalization
• In-vehicle Trailering App, System includes checklist, trailer maintenance reminders, trailer security alerts, trailer mileage, tow/haul reminder, trailer electrical diagnostics and Trailer Tire Pressure Monitor System module (Includes trailer tire pressure monitoring alert ONLY when (PTT) trailer tire pressure monitor system is factory ordered and sensors are installed.)
• Exterior Temperature Display located in radio display
• Compass, located in instrument cluster
• Window, power front, drivers express up/down
• Remote vehicle starter system
• Cruise control, steering wheel-mounted
• Theft-deterrent system, unauthorized entry
• Steering column, lock control, electrical
• Power outlet, instrument panel, 120-volt (400 watts shared with (KC9) bed mounted power outlet)
• USB ports, dual, charge-only (2nd row)
• Power outlet, bed mounted, 120-volt (400 watts shared with (KI4) instrument panel mounted power outlet)
• Air conditioning, dual-zone automatic climate control
• Air vents, rear
• Assist handles, front A-pillar mounted for driver and passenger, rear B-pillar mounted
• GMC Connected Access capable (Subject to terms. See onstar.com or dealer for details.)