Maintenance GMC SIERRA 2021 Workshop Manual

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
418 Service and Maintenance
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
This maintenance section applies to vehicles with a gasoline engine. If the vehicle has a diesel engine, see“Recommended Fluids and Lubricants”
in the Duramax diesel supplement.
Fluids and lubricants identified below by name or specification, including fluids or lubricants not listed here, can be obtained from your dealer.
Usage Fluid/Lubricant
Automatic Transmission (6-Speed Transmission) DEXRON-VI Automatic Transmission Fluid.
Automatic Transmission (8-Speed Transmission) DEXRON-HP Automatic Transmission Fluid.
Automatic Transmission (10-Speed Transmission) DEXRON ULV Automatic Transmission Fluid.
Chassis Lubrication Chassis lubricant meeting requirements of NLGI #2, Category LB or GC-LB. Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL coolant. See Cooling System
0 335.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0330.
Front and Rear Axle Driveshaft Splines See your dealer.
Front Axle (Four-Wheel Drive) and Rear Axle See your dealer. Hydraulic Brake System DOT 4 Hydraulic Brake Fluid. See Brake Fluid0343.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Service and Maintenance 419
UsageFluid/Lubricant
Key Lock Cylinders, Hood Hinges, Body Door Hinge Pins, Tailgate Hinge and Linkage, Fuel Door Hinge, Tailgate Handle Pivot Points, Hinges, Latch Bolt, and Linkage Multi-Purpose Lubricant, Superlube. See your dealer.
Transfer Case (Four-Wheel Drive) DEXRON-VI Automatic Transmission Fluid. Windshield Washer Automotive windshield washer fluid that meets regional freeze protection requirements.
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can be obtained from your dealer.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Part GM Part Number ACDelco Part Number
Engine Air Cleaner/Filter
IWith high capacity air cleaner 84121219 A3244C
IWithout high capacity air cleaner 84121217 A3246C

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
420 Service and Maintenance
PartGM Part NumberACDelco Part Number
Oil Filter
I2.7L L4 55495105
PF66
I4.3L V6 12690385
PF63E
I5.3L V8 12690385
PF63E
I6.2L V8 12690385
PF63E
Passenger Compartment Air Filter 13508023CF185
Spark Plugs
I2.7L L4 12688094
41-106-IP
I4.3L V6 12622441
41-114
I5.3L V8 12622441
41-114
I6.2L V8 12622441
41-114

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Service and Maintenance 421
PartGM Part NumberACDelco Part Number
Wiper Blades
IDriver Side –55 cm (21.7 in) 84578275
—
IPassenger Side –55 cm (21.7 in) 84578275
—

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
422 Service and Maintenance
Maintenance Records
After the scheduled services are performed, record the date, odometer reading, who performed the service, and the type of services performed
in the boxes provided. Retain all maintenance receipts.Date Odometer Reading Serviced By Services Performed

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
430 Customer Information
For further information concerning eligibility
in the Canadian Motor Vehicle Arbitration
Plan (CAMVAP), call toll-free 1-800-207-0685,
or call the General Motors Customer Care
Centre, 1-800-263-3777 (English),
1-800-263-7854 (French), or write to:
Mediation/Arbitration Program
c/o Customer Care Centre
General Motors of Canada Company
Mail Code: CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
Your inquiry should be accompanied by the
Vehicle Identification Number (VIN).
Customer Assistance Offices
GMC encourages customers to call the
toll-free number for assistance. However, if a
customer wishes to write or e-mail GMC, the
letter should be addressed to:
United States and Puerto Rico
GMC Customer Assistance Center
P.O. Box 33172
Detroit, MI 48232-5172www.gmc.com
1-800-GMC-8782 (1-800-462-8782)
1-888-889-2438 (For Text Telephone devices
(TTYs))
Roadside Assistance: 1-888-881-3302
From U.S. Virgin Islands:
1-800-496-9994
Canada
General Motors of Canada Company
Customer Care Centre, Mail Code:
CA1-163-005
1908 Colonel Sam Drive
Oshawa, Ontario L1H 8P7
www.gmc.ca
1-800-263-3777 (English)
1-800-263-7854 (French)
1-800-263-3830 (For Text Telephone Devices
(TTYs))
Roadside Assistance: 1-800-268-6800
Overseas
Please contact the local General Motors
Business Unit.
Customer Assistance for Text
Telephone (TTY) Users
To assist customers who are deaf, hard of
hearing, or speech-impaired and who use
Text Telephones (TTYs), GMC has TTY
equipment available at its Customer
Assistance Center. Any TTY user in the U.S.
can communicate with GMC by dialing:
1-888-889-2438. TTY users in Canada can dial
1-800-263-3830.
Online Owner Center
The GMC Owner Center (U.S.)
my.gmc.com
Learn more about your vehicle features,
shop for and manage your connected
services and OnStar plans, and access
diagnostic information specific to your
vehicle.
Membership Benefits
E:
Download owner’s manuals and view
vehicle-specific how-to videos.
G: View maintenance schedules, alerts, and
Vehicle Diagnostic Information. Schedule
service appointments.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
436 Customer Information
Customer Literature
Owner’s manuals are written specifically for
owners and are intended to provide basic
operational information about the vehicle.
The owner’s manual includes the
Maintenance Schedule for all models.
Customer literature publications available for
purchase include owner’s manuals, warranty
manuals, and portfolios. Portfolios include an
owner’s manual, warranty manual,
if applicable, and zip lock bag or pouch.
Current and Past Models
Service manuals and customer literature are
available for many current and past model
year GM vehicles.
To order, call 1-800-551-4123 Monday–Friday,
8:00 a.m.–6:00 p.m. eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see Helm, Inc. at:
www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.
Radio Frequency Statement
This vehicle uses license-exempt transmitters
/ receivers / systems that operate on a
radio frequency that complies with Part 15/
Part 18 of the Federal Communications
Commission (FCC) rules and with Innovation,
Science and Economic Development (ISED)
Canada's license-exempt RSS(s) / RSP-100 /
ICES-GEN.
Operation is subject to the following two
conditions:1. The device may not cause harmful interference.
2. The device must accept any interference received, including interference that may
cause undesired operation of the device.
Changes or modifications to any of these
systems by other than an authorized service
facility could void authorization to use this
equipment.
Reporting Safety Defects
Reporting Safety Defects to the
United States Government
If you believe that your vehicle has a
defect which could cause a crash or
could cause injury or death, you should
immediately inform the National
Highway Traffic Safety Administration
(NHTSA) in addition to notifying General
Motors.
If NHTSA receives similar complaints, it
may open an investigation, and if it
finds that a safety defect exists in a
group of vehicles, it may order a recall
and remedy campaign. However, NHTSA
cannot become involved in individual
problems between you, your dealer,
or General Motors.
To contact NHTSA, you may call the
Vehicle Safety Hotline toll-free at
1-888-327-4236 (TTY: 1-800-424-9153); go
to http://www.safercar.gov; or
write to:

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Connected Services 447
.Request Roadside Assistance.
.Set a parking reminder with pin drop,
take a photo, make a note, and set a
timer.
.Connect with GMC on social media.
Features are subject to change. For myGMC
mobile app information and compatibility,
see my.gmc.com.
An active OnStar or connected service plan
may be required. A compatible device,
factory-installed remote start, and power
locks are required. Data rates apply. See
www.onstar.com for details and system
limitations.
Remote Services
Contact an OnStar Advisor to unlock the
doors or sound the horn and flash the
lamps.
Marketplace
OnStar Advisors can provide offers from
restaurants and retailers on your route, help
locate hotels, or book a room. These services
vary by market.
Diagnostics
By monitoring and reporting on the vehicle's
key systems, OnStar Advanced Diagnostics,
if equipped, provides a way to keep up on
maintenance. Capabilities vary by model.
See www.onstar.com for details and system
limitations. Features are subject to change.
For updates on feature capabilities, see
my.gmc.com. Message and data rates
may apply.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
448 Index
IndexA
Accessories and Modifications . . . . . . . . . . . 323
Accessory Power . . . . . . . . . . . . . . . . . . . . . . . . . 236
Active Fuel Management . . . . . . . . . . . . . . . . 237
Adaptive Cruise Control . . . . . . . . . . . . . . . . . . 256
Add-On Electrical Equipment . . . . . . . . . . . . . .318
Adding a Snow Plow or SimilarEquipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .318
Additional Information OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Additional Maintenance and Care . . . . . . . . .415
Adjustments Lumbar, Front Seats . . . . . . . . . . . . . . . . . . . . 48
Agreements
Trademarks and License . . . . . . . . . . . . . . . 195
Air Cleaner/Filter, Engine . . . . . . . . . . . . . . . . 334
Air Conditioning . . . . . . . . . . . . . . . . . . . . 204, 206
Air Filter Life System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Air Filter, Passenger Compartment . . . . . . . 209
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
How Does an Airbag Restrain? . . . . . . . . . . 64
Passenger Sensing System . . . . . . . . . . . . . . 66
What Makes an Airbag Inflate? . . . . . . . . . 64
What Will You See after an AirbagInflates? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Airbag System (cont'd)
When Should an Airbag Inflate? . . . . . . . . 63
Where Are the Airbags? . . . . . . . . . . . . . . . . 62
Airbags Adding Equipment to the Vehicle . . . . . . . 69
Passenger Status Indicator . . . . . . . . . . . . . . 114
Readiness Light . . . . . . . . . . . . . . . . . . . . . . . . . 114
Servicing Airbag-Equipped Vehicles . . . . . . 69
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
Alarm Vehicle Security . . . . . . . . . . . . . . . . . . . . . . . . . 31
Alert
Lane Change . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
Side Blind Zone (SBZA) . . . . . . . . . . . . . . . . . 280
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 361
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 362
AM-FM Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
Antenna Fixed Mast . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Multi-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Antilock Brake System (ABS) . . . . . . . . . . . . . 246
Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Interior . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
Apple CarPlay and Android Auto . . . . . . . . . .185

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-14632426) - 2021 - CRC - 11/5/20
452 Index
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Filter, Engine Air Cleaner . . . . . . . . . . . . . . . . . . . . . 334
Fixed Mast Antenna . . . . . . . . . . . . . . . . . . . . . .158
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Flashers, Hazard Warning . . . . . . . . . . . . . . . . .142
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 Changing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Floor Console Storage . . . . . . . . . . . . . . . . . . . . . 97
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Fluid Automatic Transmission . . . . . . . . . . . . . . . 333
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Four-Wheel Drive Transfer Case . . . . . . . . 242
Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Fog Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
Folding Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Forward Collision Alert (FCA) System . . . . 275
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . 242, 346
Four-Wheel-Drive Light . . . . . . . . . . . . . . . . . . . . 118
Frequency Statement Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Front Pedestrian Braking (FPB) System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Heated and Ventilated . . . . . . . . . . . . . . . . . . 52
Fuel Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Economy, Driving for Better . . . . . . . . . . . 212
Filling a Portable Fuel Container . . . . . . . 288
Filling the Tank . . . . . . . . . . . . . . . . . . . 285, 287
Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 284
Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Low Fuel Warning Light . . . . . . . . . . . . . . . 122
Management, Active . . . . . . . . . . . . . . . . . . . 237
Prohibited Fuels . . . . . . . . . . . . . . . . . . . . . . . 284
Recommended . . . . . . . . . . . . . . . . . . . . 283, 284
Top Tier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . . . . 390
Fuses Engine Compartment Fuse Block . . . . . . . 353
Fuses and Circuit Breakers . . . . . . . . . . . . . 353
Instrument Panel Fuse Block . . . . . . 357, 358
G
Garage Door Opener . . . . . . . . . . . . . . . . . . . . . 136Programming . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
Gauges Engine Coolant Temperature . . . . . . . . . . . . 112
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . . 111
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Odometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Speedometer . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Tachometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
Trip Odometer . . . . . . . . . . . . . . . . . . . . . . . . . 110
Voltmeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Warning Lights and Indicators . . . . . . . . . 106
General Information Service and Maintenance . . . . . . . . . . . . . . 408
Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288
Vehicle Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Glass Replacement . . . . . . . . . . . . . . . . . . . . . . . 348
Global Positioning System (GPS) . . . . . . . . . . 173
Glove Box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
GM Mobility Reimbursement
Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .431
Guidance
Problems with the Route . . . . . . . . . . . . . . 174