2021 GMC SIERRA four wheel drive

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
396 Vehicle Care
Dinghy Towing (Vehicles with a
Two-Speed Transfer Case)
Only dinghy tow four-wheel-drive vehicles
with a two-speed transfer case that have an
N (Neutral) and a 4
n(Four-Wheel Drive
Low) setting.
{Warning
Shifting a four-wheel-drive vehicle's
transfer case into N (Neutral) can allow
the vehicle to move even if the
transmission is in P (Park). You or others
could be injured. Set the parking brake
and use wheel blocks before shifting the
transfer case to N (Neutral). To dinghy tow:
1. Position the vehicle being towed behind the tow vehicle, facing forward and on a
level surface.
2. Securely attach the vehicle being towed to the tow vehicle.
3. Apply the parking brake and start the engine.
4. Shift the transfer case to N (Neutral). See “Shifting into N (Neutral)” under
Four-Wheel Drive 0242.
5. With the engine running, release the parking brake and verify that the
transfer case is in N (Neutral) by shifting
the transmission to D (Drive) and then to
R (Reverse). There should be no
movement while shifting the
transmission.
6. Shift the transmission to D (Drive).
7. If equipped with an ignition key, turn the ignition to ACC/ACCESSORY.
If equipped with Keyless Access, turn the
engine off. Disregard the Shift to P (Park)
DIC message. See Ignition Positions
(Keyless Access) 0230 or
Ignition Positions (Key Access) 0229.
{Warning
To avoid death, serious injury,
or property damage, before dinghy
towing the vehicle, always disconnect and
secure the negative battery cable and
cover the negative battery post and cable
with a non-conductive material. If the
battery is left connected or the battery
cable contacts the post, the Electric
Parking Brake may activate during
towing, which could cause a crash.
8. Disconnect the negative (–) battery cable. See “Negative Battery Cable
Disconnection” inBattery - North
America 0343.
9. Shift the transmission to P (Park).
Caution
If the steering column is locked, vehicle
damage may occur.
10. Move the steering wheel to make sure the steering column is unlocked.
11. If the vehicle has an ignition key, keep it in the towed vehicle in ACC/ACCESSORY
to prevent the steering column from
locking. If the vehicle is equipped with

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Vehicle Care 397
Keyless Access, keep the RKE transmitter
outside of the vehicle and manually lock
the doors. Access the vehicle by using
the key in the door lock. SeeDoor Locks
0 21.
Disconnecting the Towed Vehicle
Before disconnecting from the tow vehicle: 1. Park on a level surface. Secure the vehicle with wheel blocks.
2. Re-connect the negative (–) battery. See Battery - North America 0343.
3. Turn on the ignition with the engine off. For vehicles with a key, turn the ignition
to ON/RUN with the engine off. If the
vehicle is equipped with Keyless Access,
with your foot off the brake pedal, press
and hold ENGINE START/STOP for
five seconds until the green light comes
on in the button. See Ignition Positions
(Keyless Access) 0230 or
Ignition Positions (Key Access) 0229.
4. Set the parking brake. See Electric
Parking Brake 0247.
5. Disconnect from the tow vehicle.
6. Shift the transmission to N (Neutral). 7. Shift the transfer case to 2m(Two-Wheel
Drive High). When the shift to 2
m
(Two-Wheel Drive High) is complete, the
light in the instrument cluster will stop
flashing and stay lit. See
Four-Wheel-Drive Light 0118.
8. Start the engine. Check that the vehicle is in 2
m(Two-Wheel Drive High) by
starting the engine and shifting the
transmission to D (Drive) and then to
R (Reverse). There should be movement
of the vehicle while shifting.
9. Shift the transmission to P (Park) and turn off the ignition.
10. Release the parking brake and remove the wheel blocks.
11. Reset any lost presets. The outside temperature display will
default to 0 °C (32 °F) but will reset with
normal usage.
Dolly Towing

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
398 Vehicle Care
Caution
Do not tow this vehicle with two wheels
on the ground, or vehicle damage could
occur. This damage would not be covered
by the vehicle warranty.
Dolly towing this vehicle is not allowed with
either the front or the rear tires on the
ground for two-wheel drive or four-wheel
drive, regardless of transfer case.
Appearance Care
Exterior Care
Locks
Locks are lubricated at the factory. Use a
de-icing agent only when absolutely
necessary, and have the locks greased after
using. See Recommended Fluids and
Lubricants 0418.
Washing the Vehicle
To preserve the vehicle's finish, wash it
often and out of direct sunlight.
{Warning
Do not power wash any part of the
vehicle’s interior, including the vinyl floor
covering. This could damage safety and
other systems in the vehicle, which
would not be covered by the vehicle
warranty.
Caution
Do not use petroleum-based, acidic,
or abrasive cleaning agents as they can
damage the vehicle's paint, metal,
or plastic parts. If damage occurs, it
would not be covered by the vehicle
warranty. Approved cleaning products can
be obtained from your dealer. Follow all
manufacturer directions regarding correct
product usage, necessary safety
precautions, and appropriate disposal of
any vehicle care product.
Caution
Avoid using high-pressure washes closer
than 30 cm (12 in) to the surface of the
vehicle. Use of power washers exceeding
8 274 kPa (1,200 psi) can result in
damage or removal of paint and decals.
Cleaning Underhood Components
Caution
Do not power wash any component
under the hood that has this
e
symbol.
This could cause damage that would not
be covered by the vehicle warranty.
Solvents or aggressive cleaners may harm
underhood components. The usages of these
chemicals should be avoided.
Recommend water only.
A pressure washer may be used, but care
must be utilized. The following criteria must
be followed:
.Water pressure must be kept below
14 000 KPa (2,000 PSI).
.Water temperature must be below 80 °C
(180 °F).

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./
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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./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

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./Cana-
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454 Index
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
LightingEntry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Illumination Control . . . . . . . . . . . . . . . . . . . 145
LED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Task . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lights Airbag Readiness . . . . . . . . . . . . . . . . . . . . . . . 114
Antilock Brake System (ABS)Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Brake System Warning . . . . . . . . . . . . . . . . . 117
Charging System . . . . . . . . . . . . . . . . . . . . . . . 115
Check Engine (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . 123
Door Ajar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Driver Mode Control . . . . . . . . . . . . . . . . . . . . 121
Electric Parking Brake . . . . . . . . . . . . . . . . . . . 117
Electronic Stability Control (ESC), Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Engine Coolant Temperature Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Engine Oil Pressure . . . . . . . . . . . . . . . . . . . . 122
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Four-Wheel-Drive . . . . . . . . . . . . . . . . . . . . . . . 118
Front Fog Lamp . . . . . . . . . . . . . . . . . . . . . . . . 123
High-Beam On . . . . . . . . . . . . . . . . . . . . . . . . . 123 Lights (cont'd)
High/Low Beam Changer . . . . . . . . . . . . . . . 141
Hill Descent Control . . . . . . . . . . . . . . . . . . . . 119
Lane Keep Assist . . . . . . . . . . . . . . . . . . . . . . . . 119
Low Fuel Warning . . . . . . . . . . . . . . . . . . . . . 122
Seat Belt Reminders . . . . . . . . . . . . . . . . . . . . 113
Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Service Electric Parking Brake . . . . . . . . . . . 118
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Tow/Haul Mode . . . . . . . . . . . . . . . . . . . . . . . . 119
Traction Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Limited-Slip Differential . . . . . . . . . . . . . . . . . . 254
Lock
Steering Column . . . . . . . . . . . . . . . . . . . . . . . . 32
Locking Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . 254
Locks Automatic Door . . . . . . . . . . . . . . . . . . . . . . . . . 22
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 22
Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Lockout Protection . . . . . . . . . . . . . . . . . . . . . . 22
Power Door . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 215
Low Fuel Warning Light . . . . . . . . . . . . . . . . . . 122
Lower Anchors and Tethers for Children (LATCH System) . . . . . . . . . . . . . . . . .77
Lumbar Adjustment . . . . . . . . . . . . . . . . . . . . . . . 48 Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48M
MaintenanceRecords . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422
Maintenance and Care Additional . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Maintenance Schedule . . . . . . . . . . . . . . . . . . . 409 Recommended Fluids andLubricants . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Transfer Case . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Malfunction Indicator Lamp . . . . . . . . . . . . . . . 115
Manual Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Manual Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . .241
Manual Windows . . . . . . . . . . . . . . . . . . . . . . . . . .41
Map Data Updates . . . . . . . . . . . . . . . . . . . . . . . . 175
Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Media
Avoiding Untrusted Devices . . . . . . . . . . . . 158
Memory Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Messages Engine Power . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Vehicle Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
Mirror Rear Camera . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
Mirrors Automatic Dimming . . . . . . . . . . . . . . . . . . . . 37
Automatic Dimming Rearview . . . . . . . . . . 38
Blind Spot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37