2023 GMC SIERRA cooling

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
386 Service and Maintenance
1 000 km/600 mi. If driven under the best
conditions, the engine oil life system may
not indicate the need for vehicle service
for up to a year. The engine oil and filter
must be changed at least once a year and
the oil life system must be reset. Your
trained dealer technician can perform this
work. If the engine oil life system is reset
accidentally, service the vehicle within
5 000 km/3,000 mi since the last service.
Reset the oil life system when the oil is
changed. SeeEngine Oil Life System
0 308.
.When the REPLACE AT NEXT OIL CHANGE
message displays, the engine air filter
should be replaced at the next engine oil
change. When the REPLACE ENGINE AIR
FILTER SOON message displays, the
engine air filter should be replaced at the
earliest convenience. Reset the engine air
filter life system after the engine air filter
is replaced. See Engine Air Filter Life
System 0309.
Every 36 000 km (22,500 mi)
.Replace passenger compartment air filter.
Or every 24 months, whichever comes
first. More frequent passenger
compartment air filter replacement may
be needed if driving in areas with heavy traffic, poor air quality, high dust levels,
or environmental allergens. Passenger
compartment air filter replacement may
also be needed if there is reduced airflow,
window fogging, or odors. Your GM
dealer can help determine when to
replace the filter.
Every 80 500 km (50,000 mi)
.Change transfer case fluid, if equipped
with 4WD. 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
transfer case fluid. Contaminated fluid will
decrease the life of the transfer case and/
or axles and should be replaced.
Every 156 000 km (97,500 mi)
.Replace spark plugs. Inspect spark plug
wires and/or boots.
Every 161 000 km (100,000 mi)
.Replace hood and/or body lift support gas
struts. Or every 10 years, whichever
comes first. See Gas Strut(s)0324.
Every 240 000 km (150,000 mi)
.Drain and fill engine cooling system. Or
every six years, whichever comes first.
See Cooling System 0311.
Severe Conditions Requiring More
Frequent Maintenance*
.Public service, military, or commercial use
vehicles to include the following:
‐ Ambulances, police cars, and
emergency rescue vehicles.
‐ Civilian vehicles such as light duty
pick-up trucks, SUVs, and passenger
cars that are used in military
applications.
‐ Recovery vehicles such as tow trucks
and flatbed single vehicle carriers or
any vehicle that is consistently used in
towing trailers or other loads.
‐ High use commercial vehicles such as
courier delivery vehicles, private
security patrol vehicles, or any vehicles
that operate on a 24–hour basis.
‐ Any vehicle consistently operated in a
high sand or dust environment such as
those used on oil pipelines and similar
applications.
.Vehicles that are regularly used for short
trips of 6 km (4 mi) or less.
The oil life indicator will show you when
to change the oil and filter. Under severe
conditions the indicator may come on
before 12 000 km (7,500 mi).

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
388 Service and Maintenance
Systems, Fluids, and Visible Leak
Inspection
.Engine oil
.Transmission
.Drive axle
.Transfer case
.Engine cooling system
.Power steering, if equipped
.Fuel system
.Windshield washer fluid
Tire Inspection
.Tire pressure, tread depth, and wear
.Rotation, if applicable
.Alignment check, optional
.Reset tire pressure monitor
.Check tire sealant expiration date,
if equipped
.Check spare tire, if equipped
Brakes
.Check brake system
Visible and Functional Inspections
.Seat belt components
.Exhaust system
.Accelerator pedal
.Passenger compartment air filter,
if equipped
.Engine air filter
.Hoses
.Belts
.Shocks and struts
.Steering components
.Axle boots or driveshaft and u-joints
.Compartment lift struts, if equipped
.Floor mats secured, no interference with
pedals
.Horn
.Ignition lock, if equipped
.Starter switch
.Evaporative control system
Lubricate
.Chassis components
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”
in Exterior Care 0374.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Service and Maintenance 389
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 (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
0 311.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0306.
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 Fluid0318.
Hydraulic Power Steering System GM Power Steering Fluid. See your dealer.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Technical Data 393
Vehicle Data
Capacities and Specifications
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and Lubricants0389.
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 the hood. See yourdealer for more information.
Engine Cooling System* 14.6 L 15.4 qt
Engine Oil with Filter 7.6 L 8.0 qt
Fuel Tank
I2500 Series and 3500 Series Standard Box (Except Double Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Standard Box (Double Cab Diesel) 111.3 L 29.4 gal
I2500 Series and 3500 Series Long Box (Except Regular Cab Diesel) 136.3 L 36.0 gal
I2500 Series and 3500 Series Long Box (Regular Cab Diesel) 106.0 L 28.0 gal

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
394 Technical Data
ApplicationCapacities
Metric English
I3500 Series Chassis Cab –Front Tank 89.0 L
23.5 gal
I3500 Series Chassis Cab –Rear Tank 151.4 L
40.0 gal
Transfer Case Fluid 2.3 L2.4 qt
Hydraulic Power Steering Fluid 2.0 L2.1 qt
Wheel Nut Torque 190Y 140 lb ft
All capacities are approximate. When adding, be sure to fill to the approximate level, as recommended in this manual. Recheck fluid level
after filling.
*Engine cooling system capacity values are based on the entire cooling system and its components.
Engine Specifications
Engine VIN CodeSpark Plug Gap
6.6L V8 (L8T) 70.95–1.10 mm (0.037–0.043 in)
Spark plug gaps are preset by the manufacturer. Re-gapping the spark plug is not recommended and can damage the spark plug.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
418 Index
Center ConsoleStorage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101
Chains, Tire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 355
Charging System Light . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Wireless . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
Check Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Child Restraints Infants and Young Children . . . . . . . . . . . . . 77
Lower Anchors and Tethers forChildren . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Older Children . . . . . . . . . . . . . . . . . . . . . . . . . . 75
Securing . . . . . . . . . . . . . . . . . . . . . . . . 92, 96, 99
Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
Child Safety Locks . . . . . . . . . . . . . . . . . . . . . . . . .25
Circuit Breakers . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Cleaning
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 374
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Climate Control Systems . . . . . . . . . . . . . . . . . 196
Air Conditioning . . . . . . . . . . . . . . . . . . . . . . . 196
Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . 197
Heating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Cluster, Instrument . . . . . . . . . . . . . . . . . . . . . . . 111
Collision Damage Repair . . . . . . . . . . . . . . . . . 402 Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
Connected Services Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415
Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Connections Connected Services . . . . . . . . . . . . . . . . . . . . 413
Control Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Traction and Electronic Stability . . . . . . . 241
Control Light Hill Descent . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . 205
Controls Steering Wheel . . . . . . . . . . . . . . . . . . . . . . . . . 151
Convex Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Coolant Engine Temperature Gauge . . . . . . . . . . . . . 117
Engine Temperature Warning Light . . . . 125
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .196, 197
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Courtesy Transportation Program . . . . . . . . 401
Coverage Explanations . . . . . . . . . . . . . . . . . . . . 171
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Customer Assistance
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398
Text Telephone (TTY) Users . . . . . . . . . . . . 398
Customer Information Publications Ordering Information . . . . . 404
Customer Satisfaction Procedure . . . . . . . . . 396
Cybersecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 406
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . 402
Danger, Warning, and Caution . . . . . . . . . . . . . .2
Dashboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Data Collection Infotainment System . . . . . . . . . . . . . . . . . . 407
OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407
Data Recorders, Event . . . . . . . . . . . . . . . . . . . 406
Database Coverage Explanations . . . . . . . . . . 171
Daytime Running Lamps (DRL) . . . . . . . . . . . . 141
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . 205
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Destination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Diagnostics Connected Services . . . . . . . . . . . . . . . . . . . . 415
Disabled Vehicle Transporting . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Distracted Driving . . . . . . . . . . . . . . . . . . . . . . . . 204
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Index 419
DoorAjar Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . 24
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Drive Belt Routing, Engine . . . . . . . . . . . . . . . 395
Drive Systems Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 321
Driver Assistance Systems . . . . . . . . . . . . . . . . . . . . 246
Information Center (DIC) . . . . . . . . . . . 128, 130
Mode Control . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Mode Control Light . . . . . . . . . . . . . . . . . . . . 125
Teen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
Driving Assistance Systems . . . . . . . . . . . . . . . . . . . . 257
Better Fuel Economy . . . . . . . . . . . . . . . . . . . 204
Characteristics and Towing Tips . . . . . . . . 268
Defensive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Distracted . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Hill and Mountain Roads . . . . . . . . . . . . . . 212
If the Vehicle is Stuck . . . . . . . . . . . . . . . . . 214
Impaired . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Loss of Control . . . . . . . . . . . . . . . . . . . . . . . . 207
Off-Road . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Off-Road Recovery . . . . . . . . . . . . . . . . . . . . . 207
Vehicle Load Limits . . . . . . . . . . . . . . . . . . . . 215
Wet Roads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Driving (cont'd)
Winter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Dual Automatic Climate Control System . . . . 197
E
E85 or FlexFuel . . . . . . . . . . . . . . . . . . . . . . . . . . 264
ElectricParking Brake . . . . . . . . . . . . . . . . . . . . . . . . . . 239
Parking Brake Light . . . . . . . . . . . . . . . . . . . . 122
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . 297
System Overload . . . . . . . . . . . . . . . . . . . . . . 327
Electrical System Engine Compartment Fuse Block . . . . . . . 329
Fuses and Circuit Breakers . . . . . . . . . . . . . 329
Instrument Panel Fuse Block . . . . . . 333, 334
Electronic Stability Control (ESC) Off Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
Engine
Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . 310
Air Filter Life System . . . . . . . . . . . . . . . . . . 309
Check Light (Malfunction Indicator) . . . . 120
Compartment Overview . . . . . . . . . . . . . . . . 305
Coolant Temperature Gauge . . . . . . . . . . . . 117
Coolant Temperature Warning Light . . . 125 Engine (cont'd)
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . 311
Drive Belt Routing . . . . . . . . . . . . . . . . . . . . . 395
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226
Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 308
Oil Pressure Gauge . . . . . . . . . . . . . . . . . . . . . 116
Oil Pressure Light . . . . . . . . . . . . . . . . . . . . . . 126
Overheated Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . 315
Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
Power Messages . . . . . . . . . . . . . . . . . . . . . . . 135
Running While Parked . . . . . . . . . . . . . . . . . 230
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Entry Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Equipment, Towing . . . . . . . . . . . . . . . . . . . . . . 276
Event Data Recorders . . . . . . . . . . . . . . . . . . . . 406
Exit Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Extended Mirrors . . . . . . . . . . . . . . . . . . . . . . . . . .37
Extended Parking . . . . . . . . . . . . . . . . . . . . . . . . 229
Extender, Seat Belt . . . . . . . . . . . . . . . . . . . . . . . 64
Exterior
Cargo Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
Lamp Controls . . . . . . . . . . . . . . . . . . . . . . . . . 139
Lamps Off Reminder . . . . . . . . . . . . . . . . . . . . 141
Lighting Battery Saver . . . . . . . . . . . . . . . . . 147