heating GMC SIERRA 2018 User Guide

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
306 Driving and Operating
Driving on Grades
Reduce speed and shift to a lower
gearbefore starting down a long or
steep downgrade. If the
transmission is not shifted down, the
brakes might get hot and no longer
work well.
Vehicles can tow in D (Drive). Shift
the transmission to a lower gear if
the transmission shifts too often
under heavy loads and/or hilly
conditions.
The Tow/Haul Mode may be used if
the transmission shifts too often.
See Tow/Haul Mode 0271.
When towing at high altitude on
steep uphill grades, consider the
following: Engine coolant will boil at
a lower temperature than at normal
altitudes. If the engine is turned off
immediately after towing at high
altitude on steep uphill grades, the
vehicle may show signs similar to
engine overheating. To avoid this,
let the engine run while parked,
preferably on level ground, with the
transmission in P (Park) for a few minutes before turning the engine
off. If the overheat warning comes
on, see
Engine Overheating 0363.
Parking on Hills
{Warning
Parking the vehicle on a hill with
the trailer attached can be
dangerous. If something goes
wrong, the rig could start to move.
People can be injured, and both
the vehicle and the trailer can be
damaged. When possible, always
park the rig on a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn
the wheels into the curb if
facing downhill or into traffic if
facing uphill.
2. Have someone place chocks under the trailer wheels. 3. When the wheel chocks are in
place, release the regular
brakes until the chocks absorb
the load.
4. Reapply the brake pedal. Then apply the parking brake and
shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
. Shift into a gear.
. Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 307
Maintenance when Trailer
Towing
The vehicle needs service more
often when pulling a trailer. See
Maintenance Schedule0448.
Things that are especially important
in trailer operation are automatic
transmission fluid, engine oil, axle
lubricant, belts, cooling system, and
brake system. It is a good idea to
inspect these before and during
the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. See Engine Overheating
0 363.
Trailer Towing
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
Do not tow a trailer during break-in.
See New Vehicle Break-In 0255.
{Warning
The driver can lose control when
pulling a trailer if the correct
equipment is not used or the
vehicle is not driven properly. For
example, if the trailer is too heavy
or the trailer brakes are
inadequate for the load, the
vehicle may not stop as expected.
The driver and passengers could
be seriously injured. The vehicle
may also be damaged; the
resulting repairs would not be
covered by the vehicle warranty.
Pull a trailer only if all the steps in
this section have been followed.
Ask your dealer for advice and
information about towing a trailer
with the vehicle.
Caution
Pulling a trailer improperly can
damage the vehicle and result in
costly repairs not covered by the
vehicle warranty. To pull a trailer
correctly, follow the advice in this
section and see your dealer for
important information about
towing a trailer with the vehicle.
See Vehicle Load Limits 0248 for
more information about the vehicle's
maximum load capacity.
To identify the trailering capacity of
the vehicle, read the information in
“Weight of the Trailer” later in this
section.
Trailering is different than just
driving the vehicle by itself.
Trailering means changes in
handling, acceleration, braking,
durability, and fuel economy.
Successful, safe trailering takes
correct equipment, and it has to be
used properly.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 341
Vehicle Care
General Information
General Information . . . . . . . . . . 342
California Proposition65 Warning . . . . . . . . . . . . . . . . . 343
California Perchlorate Materials Requirements . . . . . 343
Accessories and Modifications . . . . . . . . . . . . . . . . 343
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 344
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 344
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . . 345
Engine Oil . . . . . . . . . . . . . . . . . . . . 350
Engine Oil Life System . . . . . . . 353
Automatic Transmission Fluid (6-Speed Transmission) . . . . . 354
Automatic Transmission Fluid (8-Speed Transmission) . . . . . 357
Engine Air Cleaner/Filter . . . . . . 358
Cooling System . . . . . . . . . . . . . . 359
Engine Overheating . . . . . . . . . . 363
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . 364
Engine Fan . . . . . . . . . . . . . . . . . . . 365 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 365
Power Steering Fluid (2500/ 3500 Series) . . . . . . . . . . . . . . . . 365
Washer Fluid . . . . . . . . . . . . . . . . . 366
Brakes . . . . . . . . . . . . . . . . . . . . . . . 367
Brake Fluid . . . . . . . . . . . . . . . . . . . 368
Battery - North America . . . . . . 369
Four-Wheel Drive . . . . . . . . . . . . . 370
Front Axle . . . . . . . . . . . . . . . . . . . . 370
Rear Axle . . . . . . . . . . . . . . . . . . . . 371
Noise Control System . . . . . . . . 373
Starter Switch Check . . . . . . . . . 374
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . 374
Park Brake and P (Park) Mechanism Check . . . . . . . . . . 375
Wiper Blade Replacement . . . . 375
Windshield Replacement . . . . . 376
Gas Strut(s) . . . . . . . . . . . . . . . . . . 376
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . . . 377
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 378
Halogen Bulbs . . . . . . . . . . . . . . . . 378 High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 378
LED Lighting . . . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal, Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Electrical System
High Voltage Devices andWiring . . . . . . . . . . . . . . . . . . . . . . . 380
Electrical System Overload . . . 380
Fuses and Circuit Breakers . . . 381
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Instrument Panel Fuse Block (Right) . . . . . . . . . . . . . . . . . . . . . . 385
Instrument Panel Fuse Block (Left) . . . . . . . . . . . . . . . . . 386
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season Tires . . . . . . . . . . . . . . 389
Winter Tires . . . . . . . . . . . . . . . . . . 390
Low-Profile Tires . . . . . . . . . . . . . 390
All-Terrain Tires . . . . . . . . . . . . . . . 391
Tire Sidewall Labeling . . . . . . . . 391
Tire Designations . . . . . . . . . . . . . 393

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
360 Vehicle Care
6.0L V8 Engine
1. Coolant Surge Tank
2. Coolant Surge TankPressure Cap
3. Engine Belt-Driven Cooling Fan (Out of View)
{Warning
An underhood electric fan can
start up even when the engine is
not running and can cause injury.
Keep hands, clothing, and tools
away from any underhood
electric fan.
{Warning
Do not touch heater or radiator
hoses, or other engine parts.
They can be very hot and can
burn you. Do not run the engine if
there is a leak; all coolant could
leak out. That could cause an
engine fire and can burn you. Fix
any leak before driving the
vehicle.
Engine Coolant
The cooling system in the vehicle is
filled with DEX-COOL engine
coolant. This coolant is designed to
remain in the vehicle for 5 years or
240 000 km (150,000 mi), whichever
occurs first.
The following explains the cooling
system and how to check and add
coolant when it is low. If there is a
problem with engine overheating,
see Engine Overheating 0363.
What to Use
{Warning
Plain water, or other liquids such
as alcohol, can boil before the
proper coolant mixture will. With
plain water or the wrong mixture,
the engine could get too hot but
there would not be an overheat
warning. The engine could catch
fire and you or others could be
burned.
Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. This mixture:
. Gives freezing protection down
to−37 °C (−34 °F), outside
temperature.
. Gives boiling protection up to
129 °C (265 °F), engine
temperature.
. Protects against rust and
corrosion.
. Will not damage aluminum parts.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 363
6. Verify coolant level after theengine is shut off and the
coolant is cold. If necessary,
repeat coolant fill procedure
Steps 1–6.
Caution
If the pressure cap is not tightly
installed, coolant loss and engine
damage may occur. Be sure the
cap is properly and tightly
secured.
Engine Overheating
If the vehicle has the Duramax
diesel engine, see the Duramax
diesel supplement.
Caution
Do not run the engine if there is a
leak in the engine cooling system.
This can cause a loss of all
coolant and can damage the
system and vehicle. Have any
leaks fixed right away. The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge in the vehicle's instrument
cluster. See
Engine Coolant
Temperature Gauge 0144.
In addition, there are ENGINE
OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS
REDUCED messages in the Driver
Information Center (DIC).
If the decision is made not to lift the
hood when this warning appears,
get service help right away. See
Roadside Assistance Program
0 469.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.
4.3L V6, 5.3L V8, and 6.2L
V8 Engines
Check to see if the engine cooling
fans are running. If the engine is
overheating, the fans should be running. If they are not, do not
continue to run the engine and have
the vehicle serviced.
If Steam is Coming from the
Engine Compartment
{Warning
Steam and scalding liquids from a
hot cooling system are under
pressure. Turning the pressure
cap, even a little, can cause them
to come out at high speed and
you could be burned. Never turn
the cap when the cooling system,
including the pressure cap, is hot.
Wait for the cooling system and
pressure cap to cool.
If No Steam is Coming from
the Engine Compartment
The ENGINE OVERHEATED STOP
ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message, along with a low coolant
condition, can indicate a serious
problem.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
388 Vehicle Care
FusesUsage
19 –
20 –
22 Heating, ventilation, and air conditioning/
Auxiliary heating,
ventilation, and air
conditioning/Ignition
23 Instrument cluster/ Ignition sensing
diagnostic module/
Ignition
24 –
25 Data link connector/ Driver seat module
26 Passive entry/Passive start/Heating,
ventilation, and air
conditioning
27 – Fuses
Usage
28 –
29 Park enable/ Electrically adjustable
pedals
30 Special equipment option
31 Accessory/Run/Crank
32 Heated steering wheel
33 –
34 Instrument cluster
36 –
37 –
38 4WD transfer case electronic control
40 Left doors
41 Driver power seat Fuses
Usage
43 Left heated, cooled or ventilated seats (if
equipped)
44 Right heated, cooled or ventilated seats (if
equipped)
45 –
Relays Usage
49 Retained accessory power
50 Run/Crank

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 389
Wheels and Tires
Tires
Every new GM vehicle has
high-quality tires made by a
leading tire manufacturer. See
the warranty manual for
information regarding the tire
warranty and where to get
service. For additional
information refer to the tire
manufacturer.
{Warning
.Poorly maintained and
improperly used tires are
dangerous.
.Overloading the tires can
cause overheating as a
result of too much
flexing. There could be a
blowout and a serious
crash. SeeVehicle Load
Limits 0248.
(Continued)
Warning (Continued)
.Underinflated tires pose
the same danger as
overloaded tires. The
resulting crash could
cause serious injury.
Check all tires frequently
to maintain the
recommended pressure.
Tire pressure should be
checked when the tires
are cold.
.Overinflated tires are
more likely to be cut,
punctured, or broken by
a sudden impact —such
as when hitting a pothole.
Keep tires at the
recommended pressure.
.Worn or old tires can
cause a crash. If the
tread is badly worn,
replace them.
(Continued)
Warning (Continued)
.Replace any tires that
have been damaged by
impacts with potholes,
curbs, etc.
.Improperly repaired tires
can cause a crash. Only
the dealer or an
authorized tire service
center should repair,
replace, dismount, and
mount the tires.
.Do not spin the tires in
excess of 56 km/h
(35 mph) on slippery
surfaces such as snow,
mud, ice, etc. Excessive
spinning may cause the
tires to explode.
All-Season Tires
This vehicle may come with
all-season tires. These tires are
designed to provide good overall

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
398 Vehicle Care
Caution
Neither tire underinflation nor
overinflation is good.
Underinflated tires, or tires
that do not have enough air,
can result in:
.Tire overloading and
overheating which could
lead to a blowout.
.Premature or
irregular wear.
.Poor handling.
.Reduced fuel economy.
Overinflated tires, or tires that
have too much air, can
result in:
.Unusual wear.
.Poor handling.
.Rough ride.
.Needless damage from
road hazards. The Tire and Loading
Information label on the vehicle
indicates the original equipment
tires and the correct cold tire
inflation pressures. The
recommended pressure is the
minimum air pressure needed to
support the vehicle's maximum
load carrying capacity.
For additional information
regarding how much weight the
vehicle can carry, and an
example of the Tire and Loading
Information label, see
Vehicle
Load Limits 0248. How the
vehicle is loaded affects vehicle
handling and ride comfort. Never
load the vehicle with more
weight than it was designed to
carry.
When to Check
Check the tires once a month
or more. Do not forget the spare tire,
if the vehicle has one. See
Full-Size Spare Tire
0425 for
additional information.
How to Check
Use a good quality pocket-type
gauge to check tire pressure.
Proper tire inflation cannot be
determined by looking at the tire.
Check the tire inflation pressure
when the tires are cold, meaning
the vehicle has not been driven
for at least three hours or no
more than 1.6 km (1 mi).
Remove the valve cap from the
tire valve stem. Press the tire
gauge firmly onto the valve to
get a pressure measurement.
If the cold tire inflation pressure
matches the recommended
pressure on the Tire and
Loading Information label, no
further adjustment is necessary.
If the inflation pressure is low,
add air until the recommended
pressure is reached. If the

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Index 493
California (cont'd)Perchlorate Materials
Requirements . . . . . . . . . . . . . . . 343
California
Proposition
65 Warning . . . . . . . . . .343, 369, 426, Back Cover
Canadian Vehicle Owners . . . . . . . . 2
Capacities and Specifications . . . . . . . . . . . . . . . . . 461
Carbon Monoxide Engine Exhaust . . . . . . . . . . . . . . . 264
Tailgate . . . . . . . . . . . . . . . . . . . . . . . . . 43
Winter Driving . . . . . . . . . . . . . . . . 245
Cargo Tie-Downs . . . . . . . . . . . . . . . . . . . . 126
Cargo Lamp . . . . . . . . . . . . . . . . . . . . 183
Caution, Danger, and Warning . . . . 3
CD Player . . . . . . . . . . . . . . . . . . . . . . 195
Center Console Storage . . . . . . . . 125
Center High-Mounted Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . . . 380
Center Seat . . . . . . . . . . . . . . . . . . . . . 59
Chains, Tire . . . . . . . . . . . . . . . . . . . . 413
Charging Wireless . . . . . . . . . . . . . . . . . . . . . . 134
Charging System Light . . . . . . . . . 149 Check
Engine Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Ignition Transmission Lock . . . 374
Child Restraints Infants and Young Children . . . . . 94
Lower Anchors and Tethersfor Children . . . . . . . . . . . . . . . . . . . 99
Older Children . . . . . . . . . . . . . . . . . . 92
Securing . . . . . . . . . . . . . 111, 114, 115
Systems . . . . . . . . . . . . . . . . . . . . . . . . 96
Circuit Breakers . . . . . . . . . . . . . . . . 381
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 435
Interior Care . . . . . . . . . . . . . . . . . . 441
Climate Control
Systems . . . . . . . . . . . . . . . . . 224, 226
Air Conditioning . . . . . . . . . 224, 226
Dual Automatic . . . . . . . . . . . . . . . 228
Heating . . . . . . . . . . . . . . . . . . 224, 226
Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Cluster, Instrument . . . . . . . . . . . . . 138
Collision Damage Repair . . . . . . . 472
Compartments Storage . . . . . . . . . . . . . . . . . . . . . . . 124
Compass . . . . . . . . . . . . . . . . . . . . . . . 131
Connections OnStar . . . . . . . . . . . . . . . . . . . . . . . 482 Control
Hill Descent . . . . . . . . . . . . . . . . . . 284
Traction and Electronic
Stability . . . . . . . . . . . . . . . . . . . . . 282
Control Light Hill Descent . . . . . . . . . . . . . . . . . . 153
Control of a Vehicle . . . . . . . . . . . . . 236
Convex Mirrors . . . . . . . . . . . . . . . . . . 47
Coolant
Engine Temperature Gauge . . 144
Engine TemperatureWarning Light . . . . . . . . . . . . . . . 155
Cooling . . . . . . . . . . . . . . .224, 226, 228
Cooling System . . . . . . . . . . . . . . . . . 359
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . . . . . . 471
Cruise Control . . . . . . . . . . . . . . . . . . 285 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Cupholders . . . . . . . . . . . . . . . . . . . . . 124
Customer Assistance . . . . . . . . . . . 468 Offices . . . . . . . . . . . . . . . . . . . . . . . . 467
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 468
Customer Information Service Publications
Ordering Information . . . . . . . . 474
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 465

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
494 Index
D
Damage Repair, Collision . . . . . . . 472
Danger, Warning, and Caution . . . . 3
Data CollectionInfotainment System . . . . . . . . . . 478
OnStar . . . . . . . . . . . . . . . . . . . . . . . 478
Data Recorders, Event . . . . . . . . . 477
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 179
Defensive Driving . . . . . . . . . . . . . . . 236
Diagnostics
OnStar . . . . . . . . . . . . . . . . . . . . . . . 484
Distracted Driving . . . . . . . . . . . . . . . 235
Dome Lamps . . . . . . . . . . . . . . . . . . . 183
Door Ajar Light . . . . . . . . . . . . . . . . . . . . . 158
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
Power Locks . . . . . . . . . . . . . . . . . . . . 41
Drive Belt Routing, Engine . . . . . . 464
Driver Assistance Systems . . . . . 288
Driver Information
Center (DIC) . . . . . . . . . . . . . 158, 160
Driving Assistance Systems . . . . . . . . . . 292
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 303
Defensive . . . . . . . . . . . . . . . . . . . . . 236
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 236 Driving (cont'd)
For Better Fuel Economy . . . . . . . 33
Hill and Mountain Roads . . . . . . 245
If the Vehicle is Stuck . . . . . . . . . 247
Loss of Control . . . . . . . . . . . . . . . 238
Off-Road . . . . . . . . . . . . . . . . . . . . . 239
Off-Road Recovery . . . . . . . . . . . 238
Vehicle Load Limits . . . . . . . . . . . 248
Wet Roads . . . . . . . . . . . . . . . . . . . 244
Winter . . . . . . . . . . . . . . . . . . . . . . . . 245
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 228
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 300
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 336
Electrical System Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Fuses and Circuit Breakers . . . 381
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . 385, 386
Overload . . . . . . . . . . . . . . . . . . . . . 380
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . 480
Engine Air Cleaner/Filter . . . . . . . . . . . . . 358 Engine (cont'd)
Check Light (Malfunction
Indicator) . . . . . . . . . . . . . . . . . . . . 150
Compartment Overview . . . . . . . 345
Coolant Heater . . . . . . . . . . . . . . . 260
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 144
Coolant Temperature Warning Light . . . . . . . . . . . . . . . 155
Cooling System . . . . . . . . . . . . . . . 359
Drive Belt Routing . . . . . . . . . . . . 464
Exhaust . . . . . . . . . . . . . . . . . . . . . . 264
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 365
Oil Life System . . . . . . . . . . . . . . . 353
Oil Pressure Gauge . . . . . . . . . . 143
Oil Pressure Light . . . . . . . . . . . . 156
Overheated Protection Operating Mode . . . . . . . . . . . . . 364
Overheating . . . . . . . . . . . . . . . . . . 363
Power Messages . . . . . . . . . . . . . 164
Running While Parked . . . . . . . . 265
Starting . . . . . . . . . . . . . . . . . . . . . . . 258
Entry Lighting . . . . . . . . . . . . . . . . . . . 184
Equipment, Towing . . . . . . . . . . . . . 325
Event Data Recorders . . . . . . . . . . 477
Exit Lighting . . . . . . . . . . . . . . . . . . . . 184
Extender, Seat Belt . . . . . . . . . . . . . . 75
Exterior Lamp Controls . . . . . . . . . 176