air conditioning GMC YUKON 2018 Owner's Manual

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Introduction 3
Danger, Warning, and
Caution
Warning messages found on vehicle
labels and in this manual describe
hazards and what to do to avoid or
reduce them.
{Danger
Danger indicates a hazard with a
high level of risk which will result
in serious injury or death.
{Warning
Warning indicates a hazard that
could result in injury or death.
Caution
Caution indicates a hazard that
could result in property or vehicle
damage.
A circle with a slash through it is a
safety symbol which means“Do
Not,” “Do not do this,” or“Do not let
this happen.”
Symbols
The vehicle has components and
labels that use symbols instead of
text. Symbols are shown along with
the text describing the operation or
information relating to a specific
component, control, message,
gauge, or indicator.
M: Shown when the owner ’s
manual has additional instructions
or information.
*: Shown when the service
manual has additional instructions
or information.
0: Shown when there is more
information on another page —
“see page.” Vehicle Symbol Chart
Here are some additional symbols
that may be found on the vehicle
and what they mean. See the
features in this manual for
information.
9:
Airbag Readiness Light
#:Air Conditioning
!:Antilock Brake System (ABS)
$:Brake System Warning Light
":Charging System
I: Cruise Control
`:Do Not Puncture
^:Do Not Service
B:Engine Coolant Temperature
O:Exterior Lamps
_: Flame/Fire Prohibited
.:Fuel Gauge
+: Fuses
3:Headlamp High/Low-Beam
Changer
j: ISOFIX/LATCH System Child
Restraints

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
18 In Brief
Windshield Wiper/Washer
The windshield wiper control is on
the turn signal lever.
The windshield wipers are
controlled by turning the band
with
zFRONT on it.
1:Fast wipes.
w:Slow wipes.
3INT : Use this setting for
intermittent wipes or Rainsense™.
For intermittent wipes, turn the
zFRONT band up for more
frequent wipes or down for less
frequent wipes.
To turn on Rainsense,
press
zAUTO on the lever, then
turn the
zFRONT band on the
wiper lever to adjust the sensitivity.
. Turn the band up to a higher INT
setting for more sensitivity to
moisture.
. Turn the band down to the lower
INT setting for less sensitivity to
moisture.
Move the band out of the
3INT
position to deactivate Rainsense.
OFF : Turns the windshield
wipers off.
8: For a single wipe, turn to8,
then release. For several wipes,
hold the band on
8longer.
Lm: Push the paddle at the top of
the lever to spray washer fluid on
the windshield.
See Windshield Wiper/Washer
0 126.
Climate Controls
This system controls the heating,
cooling, and ventilation.
1. Driver Temperature Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Fan Control
5. Defrost
6. Passenger Temperature
Control
7. SYNC (Synchronized Temperature)
8. Rear Window Defogger

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
184 Climate Controls
Climate Controls
Climate Control Systems
Dual Automatic ClimateControl System . . . . . . . . . . . . . 184
Rear Climate Control System . . . . . . . . . . . . . . . . . . . . . . 188
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . 189
Maintenance
Passenger Compartment AirFilter . . . . . . . . . . . . . . . . . . . . . . . . 190
Service . . . . . . . . . . . . . . . . . . . . . . . 191
Climate Control
Systems
Dual Automatic Climate
Control System
With this system the heating,
cooling, and ventilation in the
vehicle can be controlled. Some
climate control settings can be
changed. See “Climate and Air
Quality” underVehicle
Personalization 0162.
1. Driver Temperature Control
2. A/C (Air Conditioning) 3. Air Delivery Mode Controls
4. Fan Control
5. Defrost
6. Passenger Temperature
Control
7. SYNC (Synchronized Temperature)
8. Rear Window Defogger
9. RCTRL (Rear Climate Control Lockout)
10. Rear Temperature Control
11. Rear Air Delivery Mode Control
12. Rear Fan Control
13. Front Climate Control Power Button
14. Rear AUTO (Automatic Operation)
15. Rear Climate Control Power Button
16. Air Recirculation
17. AUTO (Automatic Operation)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Climate Controls 185
Front Climate Controls
Automatic Operation
The system automatically controls
the fan speed, air delivery, air
conditioning, and recirculation in
order to heat or cool the vehicle to
the desired temperature.
When AUTO is lit, all four functions
operate automatically. Each function
can also be manually set and the
setting is displayed. Functions not
manually set will continue to be
automatically controlled, even if the
AUTO indicator is not lit.
To place the system in
automatic mode:1. Press AUTO.
2. Set the driver and passenger temperature.
To find your comfort setting,
start with 22 °C (72 °F) and
allow the system time to
stabilize. Then adjust the
temperature as needed for best
comfort. To improve fuel efficiency and to
cool the vehicle faster, recirculation
may be automatically selected in
warm weather.
The recirculation light will not come
on when automatically controlled.
Press
@to manually select
recirculation; press it again to select
outside air.
Do not cover the solar sensor on the
top of the instrument panel near the
windshield. This sensor regulates
air temperature based on sun load.
See “Sensors” later in this section.
Manual Operation
O:Press to turn the climate control
system on or off. When off is
selected, the system will stop air
from flowing into the cabin. If on is
selected, a button is pressed, or a
knob is turned, the climate control
system will turn on and operate at
the current setting.
9: Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Press
AUTO to return to automatic
operation.
The maximum auto fan speed can
be adjusted. See “Climate and Air
Quality” underVehicle
Personalization 0162.
Driver and Passenger
Temperature Control : The
temperature can be adjusted
separately for the driver and
passenger.
Turn the knob clockwise or
counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC : Press to link the passenger
and rear climate temperature
settings to the driver setting. The
SYNC indicator light will turn on.
When the passenger or rear climate
settings are adjusted, the SYNC
indicator light turns off.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
186 Climate Controls
Air Delivery Mode Control :
Press
Y,\,[, or-to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Changing the mode cancels the
automatic operation of the mode.
Press AUTO to return to automatic
operation.
Y: Air is directed to the instrument
panel outlets.
\: Air is divided between the
instrument panel and floor outlets.
[: Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
-: This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents.
0: Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The system
automatically forces outside air into
the vehicle and the air conditioning compressor will run, unless the
outside temperature is close to
freezing.
Do not drive the vehicle until all
windows are clear.
See
Air Vents 0189.
A/C : Press to turn the air
conditioning system on or off. An
indicator light comes on to show
that the air conditioning is enabled.
If the fan is turned off, the air
conditioner will not run. The A/C
light will stay on even if the outside
temperatures are below freezing.
@: Press to turn on recirculation.
An indicator light comes on. Air is
recirculated to quickly cool the
inside of the vehicle. It can also be
used to help reduce outside air and
odors that enter the vehicle. The air
conditioning compressor also comes
on when this mode is activated.
Auto Defog : The climate control
system uses a sensor to
automatically detect high humidity
inside the vehicle. When high
humidity is detected, the climate
control system may adjust to outside air supply, turn on the air
conditioner, and direct more air to
the windshield. If the climate control
system does not detect possible
window fogging, it returns to normal
operation. To turn Auto Defog off or
on, see
“Climate and Air Quality”
under Vehicle Personalization
0 162.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
K:Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on.
The rear window defogger only
works when the ignition is in on. The
defogger turns off if the ignition is
turned off or to ACC/ACCESSORY.
The rear window defogger can be
set to automatic operation. When
Auto Rear Defog is selected, the
rear window defogger turns on
automatically when the vehicle is
first started in cold weather and
turns off when the vehicle is

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Climate Controls 191
Service
All vehicles have a label underhood
that identifies the refrigerant used in
the vehicle. The refrigerant system
should only be serviced by trained
and certified technicians. The air
conditioning evaporator should
never be repaired or replaced by
one from a salvage vehicle.
It should only be replaced by a new
evaporator to ensure proper and
safe operation.
During service, all refrigerants
should be reclaimed with proper
equipment. Venting refrigerants
directly to the atmosphere is harmful
to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite,
or other health-based concerns.

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 299
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
0 266.
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-11349262) - 2018 - CRC - 11/3/17
300 Vehicle Care
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.
Engine Fan
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer towing,
high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly. The
fans will change to low speed when
additional cooling is no longer
required.
The electric engine cooling fans
may run after the engine has been
turned. off. This is normal and no
service is required.
Washer Fluid
What to Use
When windshield washer fluid needs
to be added, be sure to read the
manufacturer's instructions before
use. Use a fluid that has sufficient
protection against freezing in an
area where the temperature may fall
below freezing.
Adding Washer Fluid
The vehicle has a low washer fluid
message on the DIC that comes on
when the washer fluid is low. The
message is displayed for
15 seconds at the start of each
ignition cycle. When the WASHER
FLUID LOW ADD FLUID message
displays, washer fluid will need to
be added to the windshield washer
fluid reservoir.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. SeeEngine
Compartment Overview 0284 for
reservoir location.
Caution
. Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
. Do not use engine coolant
(antifreeze) in the
windshield washer. It can
damage the windshield
washer system and paint.
. Do not mix water with
ready-to-use washer fluid.
Water can cause the
solution to freeze and
damage the washer fluid
tank and other parts of the
washer system.
(Continued)

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 317
FusesUsage
52 –
53 –
54 –
55 –
56 –
57 –
58 –
59 Euro trailer
60 Air conditioning control
61 –
62 –
63 Upfitter 1
64 –
65 –
66 –
67 Trailer battery
68 Secondary fuel pump
69 RC upfitter 3 and 4 Fuses
Usage
70 VBAT upfitter 3 and 4
71 –
73 –
74 Engine control module/Ignition
75 Miscellaneous/ Ignition/–
76 Transmission/ Ignition
77 RC upfitter 1 and 2
78 VBAT upfitter 1 and 2
79 –
80 –
81 –
82 –
83 Euro trailer/RC
85 –
86 –
87 MAF/IAT/Humidity/ TIAP sensor Fuses
Usage
88 Injector A –odd
89 Injector B –even
90 O2 sensor B
91 Throttle control
93 Horn
94 Fog lamps
95 High-beam headlamps
96 –
97 –
98 –
99 –
100 O2 sensor A
101 Engine control module
102 Engine control module/
Transmission
control module
103 Auxiliary interior heater
104 Starter

GMC Yukon/Yukon XL/Denali Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-11349262) - 2018 - CRC - 11/3/17
Vehicle Care 323
RelaysUsage
52 Retained accessory power
Rear Compartment Fuse
Block
The rear compartment fuse block is
behind the access panel on the left
side of the compartment.
Pull the panel out by grabbing the
finger access slot at the rear edge.
The vehicle may not be equipped
with all of the fuses, relays, and
features shown. Fuses Usage
2 –
3 Right heated second row seat
4 Heated mirrors
5 Liftgate
6 Glass breakage
7 Liftglass
8 Liftgate module logic
9 Rear wiper
10 Rear heating, ventilation, and air
conditioning blower
11 Second row seat
12 Liftgate module
13 Third row seat
14 Rear accessory power outlet
15 Rear window defogger
19 Rear fog lamp (if equipped)