2010 GMC YUKON DENALI coolant level

To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pressing the fan switch will override this
delay and change the fan to a selected speed.
Manual Operation
D C(Fan Control):Press these buttons to increase or
decrease the fan speed.
Pressing either fan button while in automatic control
places the fan under manual control. The fan setting
remains displayed and the AUTO light turns off. The air
delivery mode remains under automatic control.
H G(Air Delivery Mode Control): Press these buttons
to change the direction of the airflow in the vehicle.
Repeatedly press either button until the desired mode
appears on the display. Pressing either mode button
while the system is off changes the air delivery mode
without turning the system on. Pressing either mode
button while in automatic control places the mode under
manual control.
The air delivery mode setting is displayed and the
AUTO light turns off. The fan remains under automatic
control.
H(Vent): Air is directed to the instrument panel
outlets.
)(Bi-Level): Air is divided between the instrument
panel and floor outlets. Some air is directed towards the
windshield and side window outlets.
6(Floor): Air is directed to the floor outlets, with some
to the windshield, side window outlets, and second row
floor outlets. In this mode, the system automatically
selects outside air.
-(Defog): This mode clears the windows of fog or
moisture. Air is directed to the windshield, floor outlets,
and side window vents. In this mode, the system turns
off recirculation and runs the air conditioning
compressor unless the outside temperature is close to
freezing. The recirculation mode cannot be selected
while in the defog mode.
0(Defrost): This mode removes fog or frost from the
windshield more quickly. Air is directed to the
windshield and side window vents, with some directed
to the floor vents. In this mode, the system
automatically forces outside air into the vehicle and
runs the air conditioning compressor unless the outside
temperature is close to freezing. The recirculation mode
cannot be selected while in the defrost mode.
The passenger temperature control cannot be activated
while in defrost mode. If the PASS button is pressed,
the button indicator flashes three times and will not
4-20

ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If an
overheat warning appears on the instrument panel
cluster and/or DIC, stop the vehicle as soon as
possible. See Engine Overheating
on page 6‑32for
more information.
This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle to
idle until it cools down. See Engine Coolant
Temperature Gage on page 4‑34.
See Overheated Engine Protection Operating Mode
on
page 6‑35for information on driving to a safe place in
an emergency.
ENGINE OVERHEATED STOP ENGINE
Notice: If you drive your vehicle while the engine is
overheating, severe engine damage may occur. If an
overheat warning appears on the instrument panel
cluster and/or DIC, stop the vehicle as soon as
possible. See Engine Overheating
on page 6‑32for
more information.
This message displays and a chime sounds if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it is
safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode. See
Engine Overheating
on page 6‑32for further
information.
This message also displays when the vehicle's engine
power is reduced. Reduced engine power can affect the
vehicle's ability to accelerate. If this message is on, but
there is no reduction in performance, proceed to your
destination. The performance may be reduced the next
time the vehicle is driven. The vehicle may be driven at
a reduced speed while this message is on, but
acceleration and speed may be reduced. Anytime this
message stays on, the vehicle should be taken to your
dealer/retailer for service as soon as possible.
FUEL LEVEL LOW
This message displays and a chime sounds if the fuel
level is low. Refuel as soon as possible. See Fuel Gage
on page 4‑41andFuelon page 6‑5for more
information.
HOOD OPEN
This message displays and a chime sounds if the hood
is not fully closed. Stop and turn off the vehicle, check
the hood for obstructions, and close the hood again.
Check to see if the message still appears on the DIC.
4-58

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.
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A.Engine Air Cleaner/Filter on page 6‑20.
B. Coolant Surge Tank and Pressure Cap. See Cooling System on page 6‑26.
C. Remote Positive (+) Terminal. See Jump Starting
on page 6‑42.
D. Battery on page 6‑41.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
under Engine Oil on page 6‑15.
F. Automatic Transmission Dipstick (Out of View). See “Checking the Fluid Level” underAutomatic
Transmission Fluid on page 6‑22.
G. Remote Negative (−) Terminal (GND) (Out of View). See Jump Starting on page 6‑42.
H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 6‑15.
I. Engine Cooling Fan (Out of View). See Cooling
System on page 6‑26.
J. Power Steering Fluid Reservoir (Out of View). See Power Steering Fluid on page 6‑36.
K. Brake Master Cylinder Reservoir. See “Brake
Fluid” under Brakes on page 6‑38.
L. Underhood Fuse Block on page 6‑111.
M. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on
page 6‑37.
Engine Oil
Checking Engine Oil
It is a good idea to check the engine oil level at each
fuel fill. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop.
See Engine Compartment Overview
on page 6‑14for the location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes to drain back into the oil pan. If this is not done,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
6-15

Checking Coolant
The vehicle must be on a level surface when checking
the coolant level.
Check to see if coolant is visible in the coolant surge
tank. If the coolant inside the coolant surge tank is
boiling, do not do anything else until it cools down.
If coolant is visible but the coolant level is not at or
above the FULL COLD mark, add a 50/50 mixture of
clean, drinkable water and DEX-COOL
®coolant at the
coolant surge tank, but be sure the cooling system is
cool before this is done.
The coolant surge tank is located in the engine
compartment on the passenger side of the vehicle.
See Engine Compartment Overview
on page 6‑14for more information on location.
The coolant level should be at or above the FULL
COLD mark. If it is not, you may have a leak in the
cooling system.
6-29

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 you do decide to lift the hood , make sure the vehicle
is parked on a level surface.
Then check to see if the engine cooling fans are
running. If the engine is overheating, both fans should
be running. If they are not, do not continue to run the
engine and have the vehicle serviced.
Notice:Engine damage from running your engine
without coolant is not covered by your warranty.
See Overheated Engine Protection Operating Mode
on page 6‑35for information on driving to a safe
place in an emergency.
Notice: If the engine catches fire while driving with
no coolant, the vehicle can be badly damaged.
The costly repairs would not be covered by the
vehicle warranty. See Overheated Engine Protection
Operating Mode
on page 6‑35for information on
driving to a safe place in an emergency.
If Steam Is Coming From The Engine
Compartment
{WARNING:
Steam from an overheated engine can burn you
badly, even if you just open the hood. Stay away
from the engine if you see or hear steam coming
from it. Turn it off and get everyone away from the
vehicle until it cools down. Wait until there is no
sign of steam or coolant before you open
the hood.
If you keep driving when the vehicles engine is
overheated, the liquids in it can catch fire. You or
others could be badly burned. Stop the engine if it
overheats, and get out of the vehicle until the
engine is cool.
See Overheated Engine Protection Operating
Mode
on page 6‑35for information on driving to
a safe place in an emergency.
6-33

When the Change Engine Oil Soon message displays,
certain services, checks, and inspections are required.
The services described for MaintenanceIshould be
performed at every engine oil change. The services
described for Maintenance IIshould be
performed when:
.Maintenance Iwas performed the last time the
engine oil was changed.
.It has been 10 months or more since the Change
Engine Oil Soon message has displayed or since
the last service.
Maintenance I
.Change engine oil and filter. See Engine Oilon
page 6‑15. An Emission Control Service.
.Engine coolant level check. See Engine Coolanton page 6‑27.
.Windshield washer fluid level check. See
Windshield Washer Fluid on page 6‑37.
.Tire inflation check. SeeInflation - Tire Pressureon page 6‑64.
.Tire wear inspection. See Tire Inspection and
Rotation on page 6‑71.
.Rotate tires. See Tire Inspection and Rotationon
page 6‑71.
.Fluids visual leak check (or every 12 months,
whichever occurs first). A leak in any system
must be repaired and the fluid level checked.
.Engine air cleaner filter inspection (vehicles
driven in dusty conditions only). See Engine
Air Cleaner/Filter on page 6‑20.
.Brake system inspection (or every 12 months,
whichever occurs first).
Maintenance II
.Perform all services described in Maintenance I.
.Steering and suspension inspection. Visual
inspection for damaged, loose, or missing parts or
signs of wear.
.Lubricate the front suspension, steering linkage,
and parking brake cable guides. Control arm ball
joints are maintenance‐free.
.Engine cooling system inspection. Visual
inspection of hoses, pipes, fittings, and clamps
and replacement, if needed.
7-4