2018 GMC SIERRA heater

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
234 Driving and Operating
Driving and
Operating
Driving Information
Distracted Driving . . . . . . . . . . . . 235
Defensive Driving . . . . . . . . . . . . . 236
Drunk Driving . . . . . . . . . . . . . . . . . 236
Control of a Vehicle . . . . . . . . . . . 236
Braking . . . . . . . . . . . . . . . . . . . . . . . 236
Steering . . . . . . . . . . . . . . . . . . . . . . 237
Off-Road Recovery . . . . . . . . . . . 238
Loss of Control . . . . . . . . . . . . . . . 238
Off-Road Driving . . . . . . . . . . . . . 239
Driving on Wet Roads . . . . . . . . 244
Hill and Mountain Roads . . . . . 245
Winter Driving . . . . . . . . . . . . . . . . 245
If the Vehicle Is Stuck . . . . . . . . 247
Vehicle Load Limits . . . . . . . . . . . 248
Truck-Camper LoadingInformation . . . . . . . . . . . . . . . . . . 253
Starting and Operating
New Vehicle Break-In . . . . . . . . . 255
Adjustable Throttle and BrakePedal . . . . . . . . . . . . . . . . . . . . . . . 256
Ignition Positions . . . . . . . . . . . . . 256
Starting the Engine . . . . . . . . . . . 258
Fast Idle System . . . . . . . . . . . . . 259 Retained Accessory
Power (RAP) . . . . . . . . . . . . . . . . 260
Engine Coolant Heater . . . . . . . 260
Shifting Into Park . . . . . . . . . . . . . 262
Shifting out of Park . . . . . . . . . . . 263
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 264
Active Fuel Management . . . . . 264
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 264
Running the Vehicle While Parked . . . . . . . . . . . . . . . . . . . . . . 265
Automatic Transmission
Automatic Transmission . . . . . . 265
Manual Mode . . . . . . . . . . . . . . . . . 268
Tow/Haul Mode . . . . . . . . . . . . . . . 271
Drive Systems
Four-Wheel Drive . . . . . . . . . . . . . 272
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 280
Parking Brake . . . . . . . . . . . . . . . . 281
Brake Assist . . . . . . . . . . . . . . . . . . 281
Hill Start Assist (HSA) . . . . . . . . 282
Ride Control Systems
Traction Control/Electronic Stability Control . . . . . . . . . . . . . 282 Hill Descent Control (HDC) . . . 284
Locking Rear Axle . . . . . . . . . . . . 285
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 285
Driver Assistance Systems
Driver Assistance Systems . . . 288
Assistance Systems for
Parking or Backing . . . . . . . . . . 289
Assistance Systems for Driving . . . . . . . . . . . . . . . . . . . . . . 292
Forward Collision Alert (FCA) System . . . . . . . . . . . . . . . . . . . . . . 292
Forward Automatic Braking (FAB) . . . . . . . . . . . . . . . 294
Lane Departure Warning (LDW) (2500/3500
Series) . . . . . . . . . . . . . . . . . . . . . . 295
Lane Keep Assist (LKA) (1500 Series) . . . . . . . . . . . . . . . . . . . . . . 297
Fuel
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 299
California FuelRequirements . . . . . . . . . . . . . . . 300
Fuels in Foreign Countries . . . 300
Fuel Additives . . . . . . . . . . . . . . . . 300
E85 or FlexFuel . . . . . . . . . . . . . . 300
Filling the Tank . . . . . . . . . . . . . . . 301

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
260 Driving and Operating
.Pressing the accelerator more
than one-quarter of the
way down.
. Turning the ignition off.
Retained Accessory
Power (RAP)
The following vehicle accessories
can be used for up to 10 minutes
after the engine is turned off:
.Audio System
. Power Windows
. OnStar System (if equipped)
. Sunroof (if equipped)
These features work when the key
is in ON/RUN or ACC/
ACCESSORY. Once the key is
turned from ON/RUN to LOCK/OFF,
the windows and sunroof continue
to work up to 10 minutes or until any
door is opened. The radio continues
to work for up to 10 minutes or until
the driver door is opened. Accessory Power Outlets (APOs)
The vehicle may have Accessory
Power Outlets (APOs) in several
locations. See
Power Outlets0133.
The APOs in the console or center
seat position are powered by
Retained Accessory Power (RAP).
They will continue to work for up to
10 minutes after the key is turned
from ON/RUN to LOCK/OFF, or until
the driver door is opened.
The APOs on the center stack come
from the factory powered directly
from the vehicle battery, and supply
accessory power at all times,
regardless of ignition key position.
If electronic items are left plugged
into these APOs for long periods of
time with the vehicle off, the vehicle
battery could be drained. The
vehicle may not start if the battery is
allowed to drain for an extended
period of time.
Engine Coolant Heater
The engine heater can provide
easier starting and better fuel
economy during engine warm-up in
cold weather conditions at or below
−18 °C (0 °F). Vehicles with an
engine heater should be plugged in
at least four hours before starting.
An internal thermostat in the
plug-end of the cord may exist,
which will prevent engine coolant
heater operation at temperatures
above −18 °C (0 °F).
If the vehicle has a diesel engine,
see the Duramax diesel
supplement.
{Warning
Do not plug in the engine block
heater while the vehicle is parked
in a garage or under a carport.
Property damage or personal
injury may result. Always park the
vehicle in a clear open area away
from buildings or structures.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Driving and Operating 261
To Use the Engine Coolant
Heater
1. Turn off the engine.
2. Open the hood and unwrap theelectrical cord. The cord is
secured to the driver side
fender with a clip, next to the
engine compartment fuse
block. Carefully remove the
wire tie that bundles the
electrical plug. Do not cut the
electrical cord.
Check the heater cord for
damage. If it is damaged, do
not use it. See your dealer for
a replacement. Inspect the
cord for damage yearly.
3. Plug the cord into a normal, grounded 110-volt AC outlet.
{Warning
Improper use of the heater cord
or an extension cord can damage
the cord and may result in
overheating and fire.
. Plug the cord into a
three-prong electrical utility
receptacle that is protected
by a ground fault detection
function. An ungrounded
outlet could cause an
electric shock.
. Use a weatherproof,
heavy-duty, 15 amp-rated
extension cord if needed.
Failure to use the
recommended extension
cord in good operating
condition, or using a
damaged heater or
extension cord, could make
(Continued)
Warning (Continued)
it overheat and cause a fire,
property damage, electric
shock, and injury.
. Do not operate the vehicle
with the heater cord
permanently attached to the
vehicle. Possible heater
cord and thermostat
damage could occur.
. While in use, do not let the
heater cord touch vehicle
parts or sharp edges. Never
close the hood on the
heater cord.
. Before starting the vehicle,
unplug the cord, reattach
the cover to the plug, and
securely fasten the cord.
Keep the cord away from
any moving parts.
4. Before starting the engine, be sure to unplug and store the
cord as it was before to keep it

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
262 Driving and Operating
away from moving engine
parts. If you do not, it could be
damaged.
The length of time the heater should
remain plugged in depends on
several factors. Ask a dealer in the
area where you will be parking the
vehicle for the best advice on this.
Shifting Into Park
{Warning
It can be dangerous to get out of
the vehicle if the shift lever is not
fully in P (Park) with the parking
brake firmly set. The vehicle can
roll. If you have left the engine
running, the vehicle can move
suddenly. You or others could be
injured. To be sure the vehicle will
not move, even when you are on
fairly level ground, use the steps
that follow. With four-wheel drive,
if the transfer case is in
N (Neutral), the vehicle will be
free to roll, even if the shift lever (Continued)
Warning (Continued)
is in P (Park). Be sure the transfer
case is in a drive gear. If towing a
trailer, seeDriving Characteristics
and Towing Tips 0303.
1. Hold the brake pedal down, then set the parking brake. See
Parking Brake 0281.
2. Move the shift lever into the P (Park) position by pulling the
shift lever toward you and
moving it up as far as it will go.
3. Be sure the transfer case (if equipped) is in a drive gear–
not in N (Neutral).
4. Turn the ignition off.
5. Remove the key and take it with you. If you can leave the
vehicle with the ignition key in
your hand, the vehicle is in
P (Park).
Leaving the Vehicle with the
Engine Running
{Warning
It can be dangerous to leave the
vehicle with the engine running.
The vehicle could move suddenly
if the shift lever is not fully in
P (Park) with the parking brake
firmly set.
If you have four-wheel drive and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). So be sure the transfer
case is in a drive gear –not in
N (Neutral).
And, if you leave the vehicle with
the engine running, it could
overheat and even catch fire. You
or others could be injured. Do not
leave the vehicle with the engine
running unless you have to.

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
364 Vehicle Care
If there is an engine overheat
warning, but no steam is seen or
heard, the problem may not be too
serious. Sometimes the engine can
get a little too hot when the vehicle:
.Climbs a long hill on a hot day.
. Stops after high-speed driving.
. Idles for long periods in traffic.
. Tows a trailer; see Trailer Towing
0 307.
If the ENGINE OVERHEATED
STOP ENGINE or the ENGINE
OVERHEATED IDLE ENGINE
message appears with no sign of
steam, try this for a minute or so: 1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the
highest fan speed. Open the
windows as necessary.
3. When it is safe to do so, pull off the road, shift to P (Park) or
N (Neutral) and let the
engine idle. If the temperature overheat gauge is
no longer in the overheat zone or an
overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally
and have the cooling system
checked for proper fill and function.
If the warning continues, pull over,
stop, and park the vehicle
right away.
If there is still no sign of steam and
the vehicle is equipped with an
engine driven cooling fan, push
down the accelerator until the
engine speed is about twice as fast
as normal idle speed for at least
five minutes while the vehicle is
parked. If the warning is still there,
turn off the engine and get everyone
out of the vehicle until it cools down.
If there is no sign of steam, idle the
engine for five minutes while
parked. If the warning is still
displayed, turn off the engine until it
cools down.Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message displays, an
overheat protection mode which
alternates firing groups of cylinders
helps to prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended
distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Caution
After driving in the overheated
engine protection operating
mode, the engine oil will be
severely degraded. Any repairs
performed before the engine is
cool may cause engine damage.
Allow the engine to cool before
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
384 Vehicle Care
FusesUsage
45 Fuel injectors B–even
46 O2 Sensor B
47 Throttle control
48 Horn
49 Fog lamps
50 O2 Sensor A
51 Engine control module
52 Interior heater
53 Accessory power module/TPM pump
54 Front washer
55 Air conditioning/ Battery regulated
voltage control
56 Air conditioning module/
Battery pack
57 Transmission control module/
Engine control
module Fuses
Usage
58 Headlamps
74 Electric running boards (if
equipped)
76 Fuel pump prime / MGU motor
77 Cabin pump motor
79 Vacuum pump
Relays Usage
59 Fuel pump
60 Upfitter 2
61 Upfitter 3
62 Upfitter 4
63 Trailer parking lamps
64 Run/Crank
65 Upfitter 1
66 Fuel pump 2
67 Air conditioning control
68 Starter Relays
Usage
69 Rear window defogger
70 Engine control module
71 Vacuum pump/ Cooling fan clutch
72 CKT 95
73 CKT 92
75 Fuel pump prime/ MGU motor
78 Vacuum pump switch

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