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2021 GMC Sierra 2500 HD / 3500 HD repair manual
$79.99
- Do the labor yourself. On most repairs the shop’s labor costs more than the parts. With the factory procedure you can do that part yourself.
- Built for your VIN. Your engine, transmission and options, so you don’t have to guess which section applies.
- Factory steps, specs and wiring. Repair procedures with illustrations, torque values and the complete wiring diagrams.
- Find any job in seconds. Searchable PDF with a full index and bookmarks.
- In your inbox in 12–24 hours. Yours to keep, on any computer, phone or tablet.
Description
2021 GMC Sierra 2500 HD / 3500 HD workshop manual (T1XX): factory repair procedures and wiring diagrams
The 2021 GMC Sierra 2500 HD / 3500 HD (T1XX) factory repair manual, made for your VIN from the same GM service information dealer technicians use: repair procedures, torque specs and wiring diagrams for your exact Sierra 2500 HD / 3500 HD. The 2021 Sierra 2500 HD / 3500 HD was offered with two engines and two transmissions (listed below); your manual covers the combination your VIN shows.
This page is for the heavy-duty 2021 Sierra 2500 HD and 3500 HD. For the light-duty truck, see the 2021 GMC Sierra 1500 manual.
factory-manuals.com is a Google Top Quality Store. Among stores with that badge, it is the only one where you buy the manual itself instead of renting access to it.
What you get with this manual
- Factory information, not an aftermarket book: the same GM procedures and specifications dealer technicians use
- Built for your VIN: only the engine, gearbox and options your Sierra 2500 HD / 3500 HD actually has
- One payment: no subscription, no login that expires, no monthly fee
- A PDF with working hyperlinks: click a reference in a procedure and you land on the wiring diagram, spec or step it points to. Most PDF manuals sold online are flat scans without them
- Works on any device, offline, and prints page by page for the garage
- A real person checks every order and the VIN before the manual is built
Owner's manual or repair manual?
The owner's manual in the glovebox explains the controls and the service intervals. This is the other book, the one technicians work from:
- Owner's manual: controls, warning lights, maintenance schedule, fluid types
- Factory repair manual: diagnosis by trouble code, step-by-step repairs, tightening torques, wiring diagrams and connector views
The 2021 Sierra 2500 HD / 3500 HD belongs to the T1XX Sierra HD generation, model years 2020–2026. Most procedures are shared with the other years of this generation, but options, software and wiring changed along the way, which is why the manual is built for your VIN.
Engine options
- 6.6L V8 gasoline
- 6.6L Duramax V8 turbo diesel
Gearbox options
- 6-speed automatic (gasoline)
- Allison 10-speed automatic (diesel)
The manual is made for the version in your VIN, so you don't have to work out your engine code.
Common work on a 2021 Sierra 2500 HD / 3500 HD
- Suspension links, bushings and wheel bearings
- Spark plugs and ignition coils
- Coolant and transmission fluid service
- Battery, starter and charging faults
- Sensor faults: oxygen, ABS wheel speed, mass air flow
- Glow plugs and cold-start faults
- Diesel particulate filter regeneration
- EGR valve and cooler
2021 Sierra 2500 HD / 3500 HD: recalls and known problems
The U.S. safety agency NHTSA lists 6 safety recalls and 72 owner complaints for the 2021 Sierra 2500 HD / 3500 HD. The repair steps for these systems are in the manual.
- Tires: Temporary/Emergency Spare Tire (campaign 21V578000)
- Service Brakes, Hydraulic: Control Module (campaign 21V758000)
- Seat Belts (campaign 20V792000)
- Seat Belts (campaign 20V811000)
- Latches/Locks/Linkages: Latch (campaign 24V060000)
- Power Train: Software (campaign 24V797000)
Most owner complaints concern: Power Train (20), Service Brakes (11), Engine (11), Electrical System (10), Exterior Lighting (9).
On a 2021 vehicle the 10th character of the 17-digit VIN is “M”, a quick way to confirm the model year before you order.
Other GMC manuals: 2021 Yukon, 2021 Terrain, 2021 Acadia, 2021 Canyon, 2021 Savana, 2021 Sierra.
How we make your manual
- You give us the VIN at checkout.
- We build the manual from GM data for that exact Sierra 2500 HD / 3500 HD.
- You get a PDF in your inbox within 12–24 hours, to keep on any computer, phone or tablet.
Sections of the 2021 Sierra 2500 HD / 3500 HD service manual
- General information, vehicle identification and lifting points
- Maintenance schedules, fluids and capacities
- Engine mechanical: timing, cylinder head, lubrication
- Cooling system
- Fuel system and engine management
- Ignition, starting and charging
- Emission controls
- Exhaust system
- Clutch and manual transmission
- Automatic transmission / transaxle
- Driveshafts, axles and differential
- Suspension, front and rear
- Steering
- Brakes and ABS
- Heating, ventilation and air conditioning
- Restraints and airbags
- Body, doors, glass and trim
- Lighting and instruments
- Electrical components and module locations
- Wiring diagrams
- Diagnostic trouble codes
Versions offered
Engines:
- 6.6L V8 gasoline
- 6.6L Duramax V8 turbo diesel
Transmissions:
- 6-speed automatic (gasoline)
- Allison 10-speed automatic (diesel)
Your manual is built for the version in your VIN.
Video
This video is for information. Your manual looks and works the same way, but it is not identical.
Delivery
Free, by email in 12-24 hours.
