2020 GMC SIERRA air conditioning

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
448 Service and Maintenance
Maintenance Schedule
Additional Required
Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi
60 000 km/37,500 mi
72 000 km/45,000 mi
84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi
120 000 km/75,000 mi
132 000 km/82,500 mi
144 000 km/90,000 mi
156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi
204 000 km/127,500 mi
216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services.
Check engine oil level and oil life percentage.
Change engine oil and filter, if needed. Check
engine air filter life percentage and status.
Change engine air filter, if needed.
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (1)@ @@@@@
If the vehicle is not equipped with the engine air
filter life system, replace engine air cleaner
filter. (2)@ @@
Inspect evaporative control system. (3)@@@
Replace spark plugs. Inspect spark plug wires.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires.
(2.7L L4 Turbo Engine Only)@ @
Change automatic transmission fluid and filter.@@@
For GVW under 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@@@
For GVW over 3 900 kg (8,600 lb), change
transfer case fluid, if equipped with 4WD. (4)@@@@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate
dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Service and Maintenance 449
Footnotes—Maintenance
Schedule Additional Required
Services - Severe
(1) Or every two years, whichever
comes first. More frequent
replacement may be needed if the
vehicle is driven in areas with heavy
traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter
replacement may also be needed if
you notice reduced airflow, windows
fogging up, or odors. Your local GM
Service location can help you
determine when it is the right time to
replace your filter.
(2) Or every four years, whichever
comes first. If driving in dusty
conditions, inspect the filter at each
oil change or more often as needed.
See Engine Air Cleaner/Filter 0344.
(3) Visually check all fuel and vapor
lines and hoses for proper
attachment, connection, routing, and
condition.
(4) Do not directly power wash the
transfer case and/or front/rear axle
output seals. High pressure water can overcome the seals and
contaminate the fluid. Contaminated
fluid will decrease the life of the
transfer case and/or drive axles and
should be replaced.
(5)
Or every five years, whichever
comes first. See Cooling System
0 346.
(6) Or every 10 years, whichever
comes first. Inspect for fraying,
excessive cracking, or damage;
replace, if needed.
(7) Replace brake fluid every five
years. See Brake Fluid 0357.
(8) Or every 12 months, whichever
comes first. See Wiper Blade
Replacement 0364.
(9) Or every 10 years, whichever
comes first. See Gas Strut(s)0365.
(10) Replace air conditioning
desiccant every seven years.Special Application
Services
. Vehicles with Dual Wheels:
Check dual wheel nut torque at
160, 1 600, and 10 000 km (100,
1,000, and 6,000 mi) of driving.
Repeat this service whenever a
tire/wheel is serviced or
removed.
. Severe Commercial Use
Vehicles Only: Lubricate chassis
components every oil change.
. Have underbody flushing service
performed. See “Underbody
Maintenance” inExterior Care
0 429.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-13337776) - 2020 - CRC - 4/4/19
Technical Data 459
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and
Lubricants 0453.
If the vehicle has a diesel engine, see the Duramax diesel supplement.
Application Capacities
Metric English
Air Conditioning Refrigerant For the air conditioning system refrigerant type and charge amount, see the refrigerant label under thehood. See your dealer for more information.
Engine Cooling System*
2.7L L4 Engine –1500 Series 11.8 L 12.4 qt
4.3L V6 Engine –1500 Series 11.5 L 12.2 qt
5.3L V8 Engine –1500 Series (L82) 12.8 L 13.5 qt
5.3L V8 Engine –1500 Series (L84) 13.1 L 13.8 qt
6.2L V8 Engine –1500 Series 12.6 L 13.3 qt
6.6L V8 Gas Engine –2500 Series and 3500 Series (L8T) 15.1 L 15.9 qt
Engine Oil with Filter
2.7L L4 Engine –1500 Series 5.7 L 6.0 qt

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
488 Index
IndexA
Accessories andModifications . . . . . . . . . . . . . . . . . . 329
Accessory Power . . . . . . . . . . . . . . . 217
Active Fuel Management . . . . . . . 219
Adaptive Cruise Control . . . . . . . . 245
Add-On Electrical Equipment . . . 322
Adding a Snow Plow or Similar Equipment . . . . . . . . . . . . . 323
Additional Information
OnStar . . . . . . . . . . . . . . . . . . . . . . . 479
Additional Maintenance and Care . . . . . . . . . . . . . . . . . . . . . . 450
Adjustments
Lumbar, Front Seats . . . . . . . . . . . . 57
Air Cleaner/Filter, Engine . . . . . . . 344
Air Conditioning . . . . . . . . . . . 177, 179
Air Filter Life System . . . . . . . . . . . . . . . . . . . 343
Air Filter, Passenger Compartment . . . . . . . . . . . . . . . . . 183
Air Vents . . . . . . . . . . . . . . . . . . . . . . . 182
Airbag System Check . . . . . . . . . . . . . . . . . . . . . . . . . . 84
How Does an Airbag
Restrain? . . . . . . . . . . . . . . . . . . . . . 77
Passenger Sensing System . . . . 78 Airbag System (cont'd)
What Makes an Airbag
Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 76
What Will You See after an
Airbag Inflates? . . . . . . . . . . . . . . . 77
When Should an Airbag Inflate? . . . . . . . . . . . . . . . . . . . . . . . . 76
Where Are the Airbags? . . . . . . . . 74
Airbags
Adding Equipment to theVehicle . . . . . . . . . . . . . . . . . . . . . . . . 83
Passenger Status Indicator . . . 137
Readiness Light . . . . . . . . . . . . . . 136
Servicing Airbag-Equipped Vehicles . . . . . . . . . . . . . . . . . . . . . . . 83
System Check . . . . . . . . . . . . . . . . . . 72
Alarm Vehicle Security . . . . . . . . . . . . . . . . 37
Alert Lane Change . . . . . . . . . . . . . . . . . 274
Side Blind Zone (SBZA) . . . . . . 274
All-Season Tires . . . . . . . . . . . . . . . . 379
All-Terrain Tires . . . . . . . . . . . . . . . . . 381
Antilock Brake System (ABS) . . . 232 Warning Light . . . . . . . . . . . . . . . . . 141
Appearance Care Exterior . . . . . . . . . . . . . . . . . . . . . . . 429
Interior . . . . . . . . . . . . . . . . . . . . . . . . 435

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/-
Mexico-13337776) - 2020 - CRC - 4/4/19
490 Index
Caution, Danger, and Warning . . . . 3
Center Console Storage . . . . . . . . 114
Center High-MountedStoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 369
Center Seat . . . . . . . . . . . . . . . . . . . . . 56
Chains, Tire . . . . . . . . . . . . . . . . . . . . 404
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 124
Charging System Light . . . . . . . . . 138
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 138
Ignition Transmission Lock . . . 363
Child Restraints Infants and Young Children . . . . . 87
Lower Anchors and Tethers
for Children . . . . . . . . . . . . . . . . . . . 92
Older Children . . . . . . . . . . . . . . . . . . 85
Securing . . . . . . . . . . . . 105, 108, 109
Systems . . . . . . . . . . . . . . . . . . . . . . . . 89
Circuit Breakers . . . . . . . . . . . . . . . . 370
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 429
Interior Care . . . . . . . . . . . . . . . . . . 435
Climate Control Systems . . . . . . . 177 Air Conditioning . . . . . . . . . . . . . . 177
Dual Automatic . . . . . . . . . . . . . . . 179 Climate Control Systems (cont'd)
Heating . . . . . . . . . . . . . . . . . . . . . . . 177
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Cluster, Instrument . . . . . . . . . . . . . 127
Collision Damage Repair . . . . . . . 470
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . .113
Compass . . . . . . . . . . . . . . . . . . . . . . . 121
Connected Services Connections . . . . . . . . . . . . . . . . . . 486
Diagnostics . . . . . . . . . . . . . . . . . . . 487
Navigation . . . . . . . . . . . . . . . . . . . . 485
Connections Connected Services . . . . . . . . . . 486
Control Hill Descent . . . . . . . . . . . . . . . . . . 237
Traction and ElectronicStability . . . . . . . . . . . . . . . . . . . . . 235
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 142
Control of a Vehicle . . . . . . . . . . . . . 188
Convex Mirrors . . . . . . . . . . . . . . . . . . 40
Coolant Engine Temperature Gauge . . 134
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 145
Cooling . . . . . . . . . . . . . . . . . . . . 177, 179
Cooling System . . . . . . . . . . . . . . . . . 346 Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . . 469
Cruise Control . . . . . . . . . . . . . . . . . . 243 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Cruise Control, Adaptive . . . . . . . . 245
Cupholders . . . . . . . . . . . . . . . . . . . . . 113
Customer Assistance . . . . . . . . . . . 466 Offices . . . . . . . . . . . . . . . . . . . . . . . . 465
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 466
Customer Information
Publications OrderingInformation . . . . . . . . . . . . . . . . . . 472
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 463
Cybersecurity . . . . . . . . . . . . . . . . . . . 475
D
Damage Repair, Collision . . . . . . . 470
Danger, Warning, and Caution . . . . 3
Data Collection
Infotainment System . . . . . . . . . . 476
OnStar . . . . . . . . . . . . . . . . . . . . . . . 476
Data Recorders, Event . . . . . . . . . 475
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 168
Defensive Driving . . . . . . . . . . . . . . . 187
Delayed Locking . . . . . . . . . . . . . . . . . 26