2010 GMC YUKON DENALI coolant temperature

Following Distance
Stay at least twice as far behind the vehicle ahead as
you would when driving the vehicle without a trailer.
This can help to avoid heavy braking and sudden turns.
Passing
More passing distance is needed when towing a trailer.
The combination will not accelerate as quickly and is
longer so it is necessary to go much farther beyond the
passed vehicle before returning to the lane.
Backing Up
Hold the bottom of the steering wheel with one hand.
Then, to move the trailer to the left, move that hand to
the left. To move the trailer to the right, move your hand
to the right. Always back up slowly and, if possible,
have someone guide you.
Making Turns
Notice:Making very sharp turns while trailering
could cause the trailer to come in contact with the
vehicle. The vehicle could be damaged. Avoid
making very sharp turns while trailering.
When turning with a trailer, make wider turns than
normal. Do this so the trailer will not strike soft
shoulders, curbs, road signs, trees or other objects.
Avoid jerky or sudden maneuvers. Signal well in
advance. If the trailer turn signal bulbs burn out, the arrows on the
instrument panel will still flash for turns. It is important to
check occasionally to be sure the trailer bulbs are still
working.
Driving On Grades
Reduce speed and shift to a lower gear
beforestarting
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 on page 3‑34.
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
automatic transmission in P (Park) for a few minutes
before turning the engine off. If the overheat warning
comes on, see Engine Overheating on page 6‑32.
5-57

Cooling System
The cooling system allows the engine to maintain the
correct working temperature.
A. Coolant Surge Tank
B. Coolant Surge Tank Pressure Cap
C. Engine Cooling Fan(s)
{WARNING:
An electric engine cooling fan under the hood 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:
Heater and radiator hoses, and other engine
parts, can be very hot. Do not touch them. If you
do, you can be burned. (Continued)
6-26

What to Use
{WARNING:
Adding only plain water to the cooling system
can be dangerous. Plain water, or some other
liquid such as alcohol, can boil before the proper
coolant mixture will. The vehicle's 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 −34°F (−37°C),
outside temperature.
.Gives boiling protection up to 265°F (129°C),
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's 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 7‑11for more information.
6-28

4. With the coolant surge tank pressure cap off, startthe engine and let it run until you can feel the
upper radiator hose 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 gage on your vehicle's
instrument panel. See Engine Coolant Temperature
Gage on page 4‑34.
In addition, ENGINE OVERHEATED STOP ENGINE,
ENGINE OVERHEATED IDLE ENGINE, and a ENGINE
POWER IS REDUCED message comes on in the Driver
Information Center (DIC) on the instrument panel.
See DIC Warnings and Messages on page 4‑56.
You may decide not to lift the hood when this warning
appears, but instead get service help right away.
See Roadside Assistance Program on page 8‑7.
6-32

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 an engine overheat warning is displayed but no steam
can be 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. SeeTowing a Trailer on page 5‑42. 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 gage is no longer in the
overheat zone or an overheat warning no longer
displays, the vehicle can be driven. Continue to drive
the vehicle slow for about 10 minutes. Keep a safe
vehicle distance from the car in front of you. 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.
6-34

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, you will notice a loss in power and
engine performance. This operating mode allows the
vehicle to be driven to a safe place in an emergency.
Driving extended miles (km) 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 6‑15.
Engine Fan Noise
The vehicle has electric cooling fans. You might hear
the fans spinning at low speed during most everyday
driving. The fans can turn off if no cooling is required.
Under heavy vehicle loading, trailer towing, and/or
high outside temperatures, or if you are operating the
air conditioning system, the fans can change to high
speed and you might hear an increase in fan noise.
This is normal and indicates that the cooling system is
functioning properly. The fans change to low speed
when additional cooling is no longer required.
6-35

Windshield 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 in 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, you will need to add
washer fluid 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
on page 6‑14for
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
vehicle's windshield washer system and
paint.
6-37

Cleaning (cont.)Underbody Maintenance . . . . . . . . . . . . . . . . . . . . . . . . .6-105
Washing Your Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . .6-102
Weatherstrips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-101
Windshield, Backglass, and Wiper Blades . . . . . . .6-103
Wood Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-101
Climate Control System Outlet Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-23
Rear Air Conditioning and Heating System,Electronic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-24
Climate Control Systems Dual Automatic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-18
Climate Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Clock, Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-76
Collision Damage Repair . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
Content Theft-Deterrent . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-20
Control of a Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-3
Convenience Net . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-64
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-27
Engine Temperature Gage . . . . . . . . . . . . . . . . . . . . . . . . 4-34
Cooled Seats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
Courtesy Transportation Program . . . . . . . . . . . . . . . . . . 8-10
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-8
Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-40
Cupholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62 Customer Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-6
Offices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-6
Text Telephone (TTY) Users . . . . . . . . . . . . . . . . . . . . . . . 8-6
Customer Information Service Publications Ordering Information . . . . . . . . 8-16
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . .8-2
D
Damage Repair, Collision . . . . . . . . . . . . . . . . . . . . . . . . . . 8-12
Data Recorders, Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-18
Daytime Running Lamps (DRL) . . . . . . . . . . . . . . . . . . . . 4-12
Defensive Driving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
DIC Compass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-53
Disc, MP3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-94, 4-101
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . . . . . .6-4
Dome Lamp Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Dome Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-14
Door Delayed Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Power Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Programmable Automatic Door Locks . . . . . . . . . . . . 3-10
Rear Door Security Locks . . . . . . . . . . . . . . . . . . . . . . . . 3-10
Drive Systems All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47
i - 4