coolant temperature GMC YUKON 2012 User Guide

Black plate (16,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-16 Vehicle Care
3. Remove the engine air cleaner/filter from the housing. Care
should be taken to dislodge as
little dirt as possible.
4. Clean the engine air cleaner/ filter sealing surfaces and the
housing.
5. Inspect or replace the engine air cleaner/filter.
6. Reinstall the cover and tighten the screws.
{WARNING
Operating the engine with the air
cleaner/filter off can cause you or
others to be burned. The air
cleaner not only cleans the air; it
helps to stop flames if the engine
backfires. Use caution when
working on the engine and do not
drive with the air cleaner/filter off.
Cooling System
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
The cooling system allows the
engine to maintain the correct
working temperature.
5.3L V8 Engine Shown, 6.0L
V8 Engine Similar
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s) (Out of View)

Black plate (18,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-18 Vehicle Care
What to Use
{WARNING
Adding only plain water or some
other liquid to the cooling system
can be dangerous. Plain water
and other liquids, can boil before
the proper coolant mixture will.
The coolant warning system is set
for the proper coolant mixture.
With plain water or the wrong
mixture, the engine could get too
hot but you would not get the
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.Use a 50/50 mixture of clean,
drinkable water and DEX-COOL
coolant. If using this mixture,
nothing else needs to be added.
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.
.Helps keep the proper engine
temperature.
Notice: If an improper coolant
mixture is used, the engine could
overheat and be badly damaged.
The repair cost would not be
covered by the vehicle warranty.
Too much water in the mixture
can freeze and crack the engine,
radiator, heater core, and other
parts. Notice:
If extra inhibitors and/or
additives are used in the vehicle
cooling system, the vehicle
could be damaged. Use only the
proper mixture of the engine
coolant listed in this manual for
the cooling system. See
Recommended Fluids and
Lubricants on page 11‑11 for
more information.
Never dispose of engine coolant
by putting it in the trash, pouring it
on the ground, or into sewers,
streams, or bodies of water. Have
the coolant changed by an
authorized service center, familiar
with legal requirements regarding
used coolant disposal. This will help
protect the environment and your
health.

Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-21
4. With the coolant surge tankpressure cap off, start the
engine and let it run until the
upper radiator hose can be felt
getting hot. Watch out for the
engine cooling fan.
By this time, the coolant level
inside the coolant surge tank
may be lower. If the level is
lower, add more of the proper
mixture to the coolant surge tank
until the level reaches the FULL
COLD mark. 5. Replace the pressure cap. Be
sure the pressure cap is
hand-tight and fully seated.
6. Verify coolant level after engine is shut off and the coolant is
cold. If necessary, repeat coolant
fill procedure Steps 1 through 6.
Notice: If the pressure cap is not
tightly installed, coolant loss and
possible engine damage may
occur. Be sure the cap is properly
and tightly secured.
Engine Overheating
The vehicle has several indicators
to warn of engine overheating.
There is a coolant temperature
gauge on your vehicle's instrument
panel. See Engine Coolant
Temperature Gauge on page 5‑16. In addition, ENGINE OVERHEATED
STOP ENGINE, ENGINE
OVERHEATED IDLE ENGINE, and
an ENGINE POWER IS REDUCED
message comes on in the Driver
Information Center (DIC) on the
instrument panel. See
Engine
Cooling System Messages on
page 5‑39 andEngine Power
Messages on page 5‑41.
If the decision is made not to lift the
hood when this warning appears,
but instead get service help right
away. See Roadside Assistance
Program on page 13‑5.
If the decision is made to lift the
hood, make sure the vehicle is
parked on a level surface.

Black plate (23,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-23
.Idles for long periods in traffic.
.Tows a trailer. SeeTrailer
Towing on page 9‑72.
If the overheat warning is displayed
with no sign of steam:
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. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If 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. If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes
while parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message is displayed,
an overheat protection mode which
alternates firing groups of cylinders
helps 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.
Notice:
After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10‑8.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing, and/
or high outside temperatures, the
fan speed increases as the clutch

Black plate (25,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-25
The level should be at the FULL
COLD mark. If necessary, add only
enough fluid to bring the level up to
the mark.
What to Use
To determine what kind of fluid to
use, seeRecommended Fluids and
Lubricants on page 11‑11. Always
use the proper fluid.
Notice: Use of the incorrect fluid
may damage the vehicle and the
damages may not be covered by
the vehicle's warranty. Always
use the correct fluid listed in
Recommended Fluids and
Lubricants on page 11‑11.
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. See Engine
Compartment Overview on
page 10‑6 for reservoir location. Notice
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.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.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for
fluid expansion if freezing
occurs, which could damage
the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in the windshield
washer. It can damage the
windshield washer system
and paint.

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-3
Chains, Tire . . . . . . . . . . . . . . . . . . 10-70
Charging System Light . . . . . . . . 5-20
CheckEngine Light . . . . . . . . . . . . . . . . . . 5-21
IgnitionTransmission Lock . . . . . . . . 10-33
Child Restraints
Infants and YoungChildren . . . . . . . . . . . . . . . . . . . . . 3-47
Lower Anchors and Tethers for Children . . . . . . . . . 3-53
Older Children . . . . . . . . . . . . . . . . 3-45
Securing . . . . . . . . . . . . . . . . 3-60, 3-63
Systems . . . . . . . . . . . . . . . . . . . . . . 3-50
Circuit Breakers . . . . . . . . . . . . . . 10-40
Cleaning Exterior Care . . . . . . . . . . . . . . . 10-98
Interior Care . . . . . . . . . . . . . . . 10-101
Climate Control Systems . . . . . . . 8-1 Air Conditioning . . . . . . . . . . . . . . . 8-1
Dual Automatic . . . . . . . . . . . . . . . . 8-4
Heating . . . . . . . . . . . . . . . . . . . . . . . . 8-1
Rear . . . . . . . . . . . . . . . . . . . . 8-10, 8-11 Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-8
Cluster, Instrument . . . . . . . . . . . . 5-12
Collision Damage Repair . . . . . . 13-9
Compass . . . . . . . . . . . . . . . . . . . . . . . 5-6
Connections, OnStar
®. . . . . . . . . 14-4
Continuous Damping Control (CDC) . . . . . . . . . . . . . . . . 9-50
Control of a Vehicle . . . . . . . . . . . . . 9-3
Convex Mirrors . . . . . . . . . . . . . . . . 2-17
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . 10-17
Engine Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16
Cooling System . . . . . . . . . . . . . . . 10-16 Engine Messages . . . . . . . . . . . . 5-39
Courtesy Transportation
Program . . . . . . . . . . . . . . . . . . . . . . 13-8
Cover Cargo . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Cruise Control . . . . . . . . . . . . . . . . . 9-51 Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Cupholders . . . . . . . . . . . . . . . . . . . . . 4-1 Customer Assistance . . . . . . . . . . 13-4
Offices . . . . . . . . . . . . . . . . . . . . . . . . 13-3
Text Telephone (TTY)
Users . . . . . . . . . . . . . . . . . . . . . . . 13-4
Customer Information Service PublicationsOrdering Information . . . . . . 13-12
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . 13-1
D
Damage Repair, Collision . . . . . . 13-9
Danger, Warnings, andCautions . . . . . . . . . . . . . . . . . . . . . . . . iv
Data Recorders, Event . . . . . . . 13-14
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . 6-3
Defensive Driving . . . . . . . . . . . . . . . 9-3
Delayed Locking . . . . . . . . . . . . . . . . 2-8
Devices, Auxiliary . . . . . . . . . . . . . 7-30
Diagnostics, OnStar
®. . . . . . . . . . 14-5
Distracted Driving . . . . . . . . . . . . . . . 9-2
Dome Lamps . . . . . . . . . . . . . . . . . . . 6-8

Black plate (4,1)GMC Yukon/Yukon XL Owner Manual - 2012
i-4 INDEX
DoorAjar Messages . . . . . . . . . . . . . . . 5-39
Delayed Locking . . . . . . . . . . . . . . . 2-8
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . 2-7
Power Locks . . . . . . . . . . . . . . . . . . . 2-8
Drive Belt Routing, Engine . . . . . 12-4
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . 5-29
Driving Characteristics andTowing Tips . . . . . . . . . . . . . . . . . 9-68
Defensive . . . . . . . . . . . . . . . . . . . . . . 9-3
Drunk . . . . . . . . . . . . . . . . . . . . . . . . . . 9-3
For Better Fuel Economy . . . . . 1-27
Highway Hypnosis . . . . . . . . . . . . 9-12
Hill and Mountain Roads . . . . . . 9-13
If the Vehicle is Stuck . . . . . . . . . 9-15
Loss of Control . . . . . . . . . . . . . . . . 9-5
Off-Road . . . . . . . . . . . . . . . . . . . . . . 9-6
Off-Road Recovery . . . . . . . . . . . . 9-5
Vehicle Load Limits . . . . . . . . . . . 9-16
Wet Roads . . . . . . . . . . . . . . . . . . . 9-11
Winter . . . . . . . . . . . . . . . . . . . . . . . . 9-13
Dual Automatic Climate Control System . . . . . . . . . . . . . . . . 8-4 DVD
Rear Seat Entertainment
System . . . . . . . . . . . . . . . . . . . . . . 7-34
DVD/CD Player . . . . . . . . . . . . . . . . 7-19
E
E85 Fuel . . . . . . . . . . . . . . . . . . . . . . . 9-64
Electrical Equipment, Add-On . . . . . . . . . . . . . . . . . . . . . . 9-86
Electrical System Engine CompartmentFuse Block . . . . . . . . . . . . . . . . 10-41
Fuses and Circuit
Breakers . . . . . . . . . . . . . . . . . . 10-40
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-45
Overload . . . . . . . . . . . . . . . . . . . 10-39
Emergency, OnStar
®. . . . . . . . . . 14-2
Engine Air Cleaner/Filter . . . . . . . . . . . 10-15
Check and Service EngineSoon Light . . . . . . . . . . . . . . . . . . 5-21
Compartment Overview . . . . . . . 10-6
Coolant . . . . . . . . . . . . . . . . . . . . . 10-17
Coolant Temperature
Gauge . . . . . . . . . . . . . . . . . . . . . . 5-16 Engine (cont'd)
Cooling System . . . . . . . . . . . . . 10-16
Cooling System Messages . . . 5-39
Drive Belt Routing . . . . . . . . . . . . 12-4
Exhaust . . . . . . . . . . . . . . . . . . . . . . 9-30
Fan . . . . . . . . . . . . . . . . . . . . . . . . . 10-23
Heater . . . . . . . . . . . . . . . . . . . . . . . . 9-26
Oil Pressure Gauge . . . . . . . . . . 5-15
Overheated Protection
Operating Mode . . . . . . . . . . . 10-23
Overheating . . . . . . . . . . . . . . . . 10-21
Power Messages . . . . . . . . . . . . . 5-41
Pressure Light . . . . . . . . . . . . . . . . 5-27
Running While Parked . . . . . . . . 9-30
Starting . . . . . . . . . . . . . . . . . . . . . . . 9-24
Engine Oil Life System . . . . . . . . . . . . . . . . . 10-10
Messages . . . . . . . . . . . . . . . . . . . . 5-40
Entry Lighting . . . . . . . . . . . . . . . . . . . 6-9
Equipment, Towing . . . . . . . . . . . . 9-76
Event Data Recorders . . . . . . . . 13-14
Exit Lighting . . . . . . . . . . . . . . . . . . . . 6-9
Extender, Safety Belt . . . . . . . . . . 3-28
Exterior Lamp Controls . . . . . . . . . 6-1
Exterior Lamps Off Reminder . . . 6-2

Black plate (5,1)GMC Yukon/Yukon XL Owner Manual - 2012
INDEX i-5
F
FanEngine . . . . . . . . . . . . . . . . . . . . . . 10-23
Features Memory . . . . . . . . . . . . . . . . . . . . . . . . 1-9
Filter, Engine Air Cleaner . . . . . . . . . 10-15
Flash-to-Pass . . . . . . . . . . . . . . . . . . . 6-3
Flashers, Hazard Warning . . . . . . 6-5
Flat Tire . . . . . . . . . . . . . . . . . . . . . . 10-71 Changing . . . . . . . . . . . . . . . . . . . 10-72
Floor Mats . . . . . . . . . . . . . . . . . . .10-104
Fluid Automatic Transmission . . . . 10-12
Brakes . . . . . . . . . . . . . . . . . . . . . . 10-27
Four-Wheel DriveTransfer Case . . . . . . . . . 9-37, 9-42
Power Steering . . . . . . . . . . . . . 10-24
Washer . . . . . . . . . . . . . . . . . . . . . 10-25
Fog Lamps
Bulb Replacement . . . . . . . . . . . . . 6-6
Folding Mirrors . . . . . . . . . . . . . . . . 2-18
Four-Wheel Drive . . . . . . . . . . . . 10-29, 9-37, 9-42 Front Axle . . . . . . . . . . . . . . . . . . . . 10-30
Front Fog Lamp
Light . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Front Seats Adjustment . . . . . . . . . . . . . . . . . . . . 3-3
Heated and Ventilated . . . . . . . . . 3-9
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-61
Additives . . . . . . . . . . . . . . . . . . . . . 9-63
E85 (85% Ethanol) . . . . . . . . . . . 9-64
Filling a Portable FuelContainer . . . . . . . . . . . . . . . . . . . 9-67
Filling the Tank . . . . . . . . . . . . . . . 9-65
Fuels in Foreign Countries . . . . 9-62
Gasoline Specifications . . . . . . . 9-62
Gauge . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Low Fuel Warning Light . . . . . . . 5-27
Management, Active . . . . . . . . . . 9-29
Recommended . . . . . . . . . . . . . . . 9-62
Requirements, California . . . . . 9-62
System Messages . . . . . . . . . . . . 5-41
Fuel Economy
Driving . . . . . . . . . . . . . . . . . . . . . . . . 1-27
Full-Size Spare Tire . . . . . . . . . . 10-87 Fuses
Engine Compartment
Fuse Block . . . . . . . . . . . . . . . . 10-41
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-40
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . . 10-45
G
Garage Door Opener . . . . . . . . . . 5-55
Programming . . . . . . . . . . . . . . . . . 5-55
Gasoline Specifications . . . . . . . . . . . . . . . . . 9-62
Gauges Engine CoolantTemperature . . . . . . . . . . . . . . . . 5-16
Engine Oil Pressure . . . . . . . . . . 5-15
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 5-14
Odometer . . . . . . . . . . . . . . . . . . . . . 5-13
Speedometer . . . . . . . . . . . . . . . . . 5-13
Tachometer . . . . . . . . . . . . . . . . . . . 5-13
Trip Odometer . . . . . . . . . . . . . . . . 5-13
Voltmeter . . . . . . . . . . . . . . . . . . . . . 5-17
Warning Lights and Indicators . . . . . . . . . . . . . . . . . . . 5-11