2020 GMC YUKON heater

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
208 Driving and Operating
at or below−18 °C (0 °F). Vehicles
with an engine heater should be
plugged in at least four hours before
starting. There may be an internal
thermostat in the plug end of the
cord, which will prevent engine
heater operation at temperatures
above −18 °C (0 °F).
To Use the Engine Heater
1. Turn off the engine.
2. Open the hood and unwrap the
electrical cord. The cord is by
the left front fender, next to the
engine compartment fuse
block.
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 Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Driving and Operating 209
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.
Retained Accessory
Power (RAP)
When the ignition is turned from on
to off, the following features (if
equipped) will continue to function
for up to 10 minutes, or until the
driver door is opened. These
features will also work when the
ignition is in RUN or ACC/
ACCESSORY:
. Infotainment System
. Power Windows (during RAP
this functionality will be lost
when any door is opened)
. Sunroof (during RAP this
functionality will be lost when
any door is opened)
. Auxiliary Power Outlet .
Audio System
. OnStar System
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. If the vehicle has a
four-wheel-drive transfer case
with an N (Neutral) position, and
the transfer case is in N (Neutral),
the vehicle will be free to roll,
even if the shift lever is in
P (Park). Be sure the transfer
case is in a drive gear. If towing a
trailer, see Driving Characteristics
and Towing Tips 0259. 1. Hold the brake pedal down,
then set the parking brake. See
Parking Brake 0225.
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 is in a drive gear –not in
N (Neutral).
4. Push the ignition key in, towards the steering column
and then 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
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Vehicle Care 297
{Warning
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. Use caution
when working on the engine. Do
not start the engine or drive the
vehicle with the air cleaner/filter
off, as flames may be present if
the engine backfires.
Caution
If the air cleaner/filter is off, dirt
can easily get into the engine,
which could damage it. Always
have the air cleaner/filter in place
when driving.
Cooling System
The cooling system allows the
engine to maintain the correct
working temperature.
1. Coolant Surge Tank
2. Coolant Surge TankPressure Cap
3. Engine Electric Cooling Fan(s)
{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 0300.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
Vehicle Care 301
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.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
0 264.
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 engine coolant temperature
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.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-13566587) - 2020 - CRC - 4/15/19
320 Vehicle Care
FusesUsage
102 Engine control module/
Transmission
control module
103 Auxiliary interior heater
104 Starter
105 –
106 –
107 Aeroshutter
108 –
109 Police upfitter 110 –
111 –
113 –
114 Front windshield washer
115 Rear window washer
116 Left cooling fan
117 Fuel pump prime
118 – Fuses
Usage
119 –
120 –
121 Right HID headlamp
122 Left HID headlamp
123 Right cooling fan
Relays Usage
9 Fuel pump
29 Upfitter 2
37 Upfitter 3
48 Upfitter 4
51 Parking lamp
64 Secondary fuel pump
72 Upfitter 1
84 Run/Crank
92 Engine control module
112 Starter
120 Fuel pump primeInstrument Panel Fuse
Block (Right)
The right instrument panel fuse
block access door is on the
passenger side edge of the
instrument panel.
Pull off the cover to access the fuse
block.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13566587) - 2020 - CRC - 4/15/19
424 Index
DrivingAssistance Systems . . . . . . . . . . 245
Better Fuel Economy . . . . . . . . . 184
Characteristics and
Towing Tips . . . . . . . . . . . . . . . . . 259
Defensive . . . . . . . . . . . . . . . . . . . . . 185
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . 185
Hill and Mountain Roads . . . . . . 193
If the Vehicle is Stuck . . . . . . . . . 195
Loss of Control . . . . . . . . . . . . . . . 187
Off-Road . . . . . . . . . . . . . . . . . . . . . 188
Off-Road Recovery . . . . . . . . . . . 187
Vehicle Load Limits . . . . . . . . . . . 196
Wet Roads . . . . . . . . . . . . . . . . . . . 193
Winter . . . . . . . . . . . . . . . . . . . . . . . . 194
Dual Automatic Climate
Control System . . . . . . . . . . . . . . . . 175
E
E85 or FlexFuel . . . . . . . . . . . . . . . . 255
Electrical Equipment,Add-On . . . . . . . . . . . . . . . . . . . . . . . 280
Electrical System Engine Compartment FuseBlock . . . . . . . . . . . . . . . . . . . . . . . . 315
Fuses and Circuit Breakers . . . 315
Instrument Panel Fuse
Block . . . . . . . . . . . . . . . . . . . 320, 323 Electrical System (cont'd)
Overload . . . . . . . . . . . . . . . . . . . . . 314
Rear Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 325
Emergency OnStar . . . . . . . . . . . . . . . . . . . . . . . .411
Engine Air Cleaner/Filter . . . . . . . . . . . . . 296
Check Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . 136
Compartment Overview . . . . . . . 286
Coolant Temperature Gauge . . . . . . . . . . . . . . . . . . . . . . 131
Coolant Temperature
Warning Light . . . . . . . . . . . . . . . 141
Cooling System . . . . . . . . . . . . . . . 297
Drive Belt Routing . . . . . . . . . . . . 395
Exhaust . . . . . . . . . . . . . . . . . . . . . . 212
Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Heater . . . . . . . . . . . . . . . . . . . . . . . . 207
Oil Life System . . . . . . . . . . . . . . . 291
Oil Pressure Gauge . . . . . . . . . . 130
Oil Pressure Light . . . . . . . . . . . . 142
Overheating . . . . . . . . . . . . . . . . . . 300
Power Messages . . . . . . . . . . . . . 151
Running While Parked . . . . . . . . 212
Starting . . . . . . . . . . . . . . . . . . . . . . . 206
Entry Lighting . . . . . . . . . . . . . . . . . . . 171 Equipment, Towing . . . . . . . . . . . . . 270
Event Data Recorders . . . . . . . . . . 408
Exit Lighting . . . . . . . . . . . . . . . . . . . . 171
Extended Parking . . . . . . . . . . . . . . . 211
Extender, Seat Belt . . . . . . . . . . . . . . 71
Exterior Lamp Controls . . . . . . . . . 164
Exterior Lamps Off Reminder . . . 166
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . . . 173
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . . . 302
Filter, Engine Air Cleaner . . . . . . . . . . . 296
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 167
Flashers, Hazard Warning . . . . . . 168
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 347 Changing . . . . . . . . . . . . . . . . . . . . . 349
FlexFuel E85 . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Floor Console Storage . . . . . . . . . . 111
Floor Mats . . . . . . . . . . . . . . . . . . . . . . 375
Fluid AutomaticTransmission . . . . . . . . . . . 292, 295
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 304

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./Cana-
da/Mexico-13566587) - 2020 - CRC - 4/15/19
426 Index
Headlamps (cont'd)Lamps On Reminder . . . . . . . . . 143
Heated Rear Seats . . . . . . . . . . . . . . . . . . . . . 55
Steering Wheel . . . . . . . . . . . . . . . .116
Heated and Ventilated Front Seats . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Heated Mirrors . . . . . . . . . . . . . . . . . . . 39
Heater Engine . . . . . . . . . . . . . . . . . . . . . . . . 207
Heating . . . . . . . . . . . . . . . . . . . . 175, 179
High-Beam On Light . . . . . . . . . . . . 143
High-Speed Operation . . . . . . . . . . 334
Hill and Mountain Roads . . . . . . . . 193
Hill Descent Control (HDC) . . . . . 228
Hill Start Assist (HSA) . . . . . . . . . . 225
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
How to Wear Seat Belts Properly . . . . . . . . . . . . . . . . . . . . . . . . 63
HVAC . . . . . . . . . . . . . . . . . . . . . . 175, 179
I
Ignition Positions . . . . . . . . . . 202, 204
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . . . . . 308
Immobilizer . . . . . . . . . . . . . . . . . . . . . . 36 Indicator
Vehicle Ahead . . . . . . . . . . . . . . . . 140
Infants and Young Children, Restraints . . . . . . . . . . . . . . . . . . . . . . 88
Information Publication Ordering . . . . . . . . . . 405
Infotainment . . . . . . . . . . . . . . . . . . . . 174
Infotainment System . . . . . . . . . . . . 409
Instrument Cluster . . . . . . . . . . . . . . 126
Instrument Panel Overview . . . . . . . 5
Interior Rearview Mirrors . . . . . . . . . 41
Introduction . . . . . . . . . . . . . . . . . . . . . . . 2
J
Jump Starting - North
America . . . . . . . . . . . . . . . . . . . . . . . 360
K
Keyless EntryRemote (RKE) System . . . . . 13, 16
Keys . . . . . . . . . . . . . . . . . . . . . . . . . . .9, 10
L
Labeling, Tire Sidewall . . . . . . . . . . 329
Lamps Daytime Running (DRL) . . . . . . 167
Dome . . . . . . . . . . . . . . . . . . . . . . . . . 170
Exterior Controls . . . . . . . . . . . . . . 164 Lamps (cont'd)
Exterior Lamps Off
Reminder . . . . . . . . . . . . . . . . . . . 166
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 173
License Plate . . . . . . . . . . . . . . . . . 314
Malfunction Indicator (Check Engine) . . . . . . . . . . . . . 136
On Reminder . . . . . . . . . . . . . . . . . 143
Reading . . . . . . . . . . . . . . . . . . . . . . 171
Lane Change Alert (LCA) . . . . . . . 250
Lane Keep Assist (LKA) . . . . . . . . 251
Lane Keep Assist Light . . . . . . . . . 139
Lap Belt . . . . . . . . . . . . . . . . . . . . . . . . . 71
Lap-Shoulder Belt . . . . . . . . . . . . . . . 65
LATCH System Replacing Parts after aCrash . . . . . . . . . . . . . . . . . . . . . . . 103
LATCH, Lower Anchors and Tethers for Children . . . . . . . . . . . . 93
LED Lighting . . . . . . . . . . . . . . . . . . . . 312
Level Control Automatic . . . . . . . . . . . . . . . . . . . . . 229
Liftgate . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Lighting Entry . . . . . . . . . . . . . . . . . . . . . . . . . 171
Exit . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
Illumination Control . . . . . . . . . . . 170