2010 GMC YUKON DENALI warning

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

Parking on Hills
{WARNING:
Parking the vehicle on a hill with the trailer
attached can be dangerous. If something goes
wrong, the rig could start to move. People can be
injured, and both the vehicle and the trailer can be
damaged. When possible, always park the rig on
a flat surface.
If parking the rig on a hill: 1. Press the brake pedal, but do not shift into P (Park) yet. Turn the wheels into the curb if facing downhill
or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the regular brakes until the chocks absorb the load.
4. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
2. Start the engine
3. Shift into a gear
4. Release the parking brake
5. Let up on the brake pedal.
6. Drive slowly until the trailer is clear of the chocks.
7. Stop and have someone pick up and store the chocks.
Maintenance When Trailer Towing
The vehicle needs service more often when pulling a
trailer. See this manual's Maintenance Schedule or
Index for more information. Things that are especially
important in trailer operation are automatic transmission
fluid, engine oil, axle lubricant, belts, cooling system
and brake system. It is a good idea to inspect these
before and during the trip.
Check periodically to see that all hitch nuts and bolts
are tight.
5-58

Section 6 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-3
Accessories and Modifications . . . . . . . . . . . . . . . . . . 6-3
California Proposition 65 Warning . . . . . . . . . . . . . . . 6-4
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 6-4
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . . 6-8
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 6-11
Checking Things Under the Hood . . . . . . . . . . . . . . .6-12
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-12
Engine Compartment Overview . . . . . . . . . . . . . . . . 6-14
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-15
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 6-20
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . 6-22
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-26
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-27 Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32
Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-35
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 6-37
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-38
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-41
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42
All-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-47
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-48
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-49
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-50
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Taillamps, Turn Signal, Stoplamps and Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-54
Windshield Wiper Blade Replacement . . . . . . . . . . .6-55
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-57
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Tire Terminology and Definitions . . . . . . . . . . . . . . . 6-61
Inflation - Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . 6-64
6-1

California Proposition 65 Warning
Most motor vehicles, including this one, contain and/or
emit chemicals known to the State of California to
cause cancer and birth defects or other reproductive
harm. Engine exhaust, many parts and systems, many
fluids, and some component wear by-products contain
and/or emit these chemicals.
California Perchlorate Materials
Requirements
Certain types of automotive applications, such as
airbag initiators, seat belt pretensioners, and lithium
batteries contained in remote keyless transmitters,
may contain perchlorate materials. Special handling
may be necessary. For additional information,
see www.dtsc.ca.gov/hazardouswaste/perchlorate.
Doing Your Own Service Work
{WARNING:
You can be injured and the vehicle could be
damaged if you try to do service work on a vehicle
without knowing enough about it.
.Be sure you have sufficient knowledge,
experience, the proper replacement parts,
and tools before attempting any vehicle
maintenance task.
.Be sure to use the proper nuts, bolts, and
other fasteners. English and metric fasteners
can be easily confused. If the wrong fasteners
are used, parts can later break or fall off.
You could be hurt.
If doing some of your own service work, use the proper
service manual. It tells you much more about how to
service the vehicle than this manual can. To order the
proper service manual, see Service Publications
Ordering Information on page 8‑16.
6-4

Filling the Tank
{WARNING:
Fuel vapor burns violently and a fuel fire can
cause bad injuries. To help avoid injuries to you
and others, read and follow all the instructions on
the fuel pump island. Turn off the engine when
refueling. Do not smoke near fuel or when
refueling the vehicle. Do not use cellular phones.
Keep sparks, flames, and smoking materials away
from fuel. Do not leave the fuel pump unattended
when refueling the vehicle. This is against the law
in some places. Do not re-enter the vehicle while
pumping fuel. Keep children away from the fuel
pump; never let children pump fuel.
The tethered fuel cap is located behind a hinged fuel
door on the driver side of the vehicle. If the vehicle
has E85 fuel capability, the fuel cap will be yellow and
state that E85 or gasoline can be used. SeeFuel E85
(85% Ethanol) on page 6‑7.
6-9

To open the fuel door, push the rearward center edge in
and release and it will open.
To remove the fuel cap, turn it slowly counterclockwise.
The fuel cap has a spring in it; if the cap is released too
soon, it will spring back to the right.
While refueling, hang the tethered fuel cap from the
hook on the fuel door.
{WARNING:
Fuel can spray out on you if you open the fuel cap
too quickly. If you spill fuel and then something
ignites it, you could be badly burned. This spray
can happen if the tank is nearly full, and is more
likely in hot weather. Open the fuel cap slowly and
wait for any hiss noise to stop. Then unscrew the
cap all the way.
Be careful not to spill fuel. Do not top off or overfill the
tank and wait a few seconds after you have finished
pumping before removing the nozzle. Clean fuel from
painted surfaces as soon as possible. See Washing
Your Vehicle on page 6‑102.
When replacing the fuel cap, insert the tether in its hole
before tightening the cap. Turn the fuel cap clockwise
until it clicks. It will require more effort to turn the fuel
cap on the last turn as you tighten it. Make sure the cap
is fully installed. The diagnostic system can determine if
the fuel cap has been left off or improperly installed.
This would allow fuel to evaporate into the atmosphere.
See Malfunction Indicator Lamp on page 4‑35
6-10

If the vehicle has a Driver Information Center (DIC), the
TIGHTEN GAS CAP message displays if the fuel cap is
not properly installed.
{WARNING:
If a fire starts while you are refueling, do not
remove the nozzle. Shut off the flow of fuel by
shutting off the pump or by notifying the station
attendant. Leave the area immediately.
Notice: If you need a new fuel cap, be sure to get
the right type. Your dealer/retailer can get one for
you. If you get the wrong type, it may not fit
properly. This may cause the malfunction indicator
lamp to light and may damage the fuel tank and
emissions system. See Malfunction Indicator Lamp
on page 4‑35.
Filling a Portable Fuel Container
{WARNING:
Never fill a portable fuel container while it is in
the vehicle. Static electricity discharge from the
container can ignite the fuel vapor. You can be
badly burned and the vehicle damaged if this
occurs. To help avoid injury to you and others:
.Dispense fuel only into approved containers.
.Do not fill a container while it is inside a
vehicle, in a vehicle's trunk, pickup bed,
or on any surface other than the ground.
.Bring the fill nozzle in contact with the inside
of the fill opening before operating the nozzle.
Contact should be maintained until the filling is
complete.
.Do not smoke while pumping fuel.
.Do not use a cellular phone while
pumping fuel.
6-11

Checking Things Under
the Hood
{WARNING:
An electric fan under the hood can start up and
injure you even when the engine is not running.
Keep hands, clothing, and tools away from any
underhood electric fan.
{WARNING:
Things that burn can get on hot engine parts and
start a fire. These include liquids like fuel, oil,
coolant, brake fluid, windshield washer and other
fluids, and plastic or rubber. You or others could
be burned. Be careful not to drop or spill things
that will burn onto a hot engine.
Hood Release
To open the hood:
1. Pull the handle withthis symbol on it. It is
located inside the
vehicle to the lower left
of the steering wheel.
6-12