2010 GMC YUKON DENALI engine

Towing
Towing Your Vehicle
To avoid damage, the disabled vehicle should be towed
with all four wheels off the ground. Consult your dealer/
retailer or a professional towing service if the disabled
vehicle must be towed. SeeRoadside Assistance
Program on page 8‑7.
To tow the vehicle behind another vehicle for
recreational purposes, such as behind a motorhome,
see “Recreational Vehicle Towing” following.
Recreational Vehicle Towing
If the vehicle has a two–mode hybrid engine, see the
Two–mode Hybrid manual for more information.
Recreational vehicle towing means towing the vehicle
behind another vehicle–such as behind a motorhome.
The two most common types of recreational vehicle
towing are known as “dinghy towing”(towing the vehicle
with all four wheels on the ground) and “dolly towing”
(towing the vehicle with two wheels on the ground and
two wheels up on a device known as a “dolly”).Here are some important things to consider before
recreational vehicle towing:
.What is the towing capacity of the towing vehicle?
Be sure to read the tow vehicle manufacturer's
recommendations.
.What is the distance that will be travelled? Some
vehicles have restrictions on how far and how long
they can tow.
.Is the proper towing equipment going to be used?
See your dealer/retailer or trailering professional
for additional advice and equipment
recommendations.
.Is the vehicle ready to be towed? Just as preparing
the vehicle for a long trip, make sure the vehicle is
prepared to be towed. See
Before Leaving on a
Long Trip on page 5‑25.
5-37

Pulling A Trailer
Here are some important points:
.There are many different laws, including speed
limit restrictions, having to do with trailering. Make
sure the rig will be legal, not only where you live
but also where you will be driving. A good source
for this information can be state or provincial
police.
.Consider using a sway control. See“Hitches”later
in this section.
.Do not tow a trailer at all during the first 500 miles
(800 km) the new vehicle is driven. The engine,
axle or other parts could be damaged.
.Then, during the first 500 miles (800 km) that a
trailer is towed, do not drive over 50 mph (80 km/h)
and do not make starts at full throttle. This helps
the engine and other parts of the vehicle wear in at
the heavier loads.
.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.
.If the vehicle has the Side Blind Zone Alert (SBZA)
system and it doesn't seem to be working properly
while pulling a trailer, turn the system off. See Side
Blind Zone Alert (SBZA)
on page 3‑47for more
information.
Important considerations that have to do with weight:
.The weight of the trailer
.The weight of the trailer tongue
.The weight on the vehicle's tires
.And the weight of the trailering combination
5-43

Tow/Haul Mode
Pressing this button at the end of the shift lever turns on
and off the tow/haul mode.
This indicator light on the
instrument panel cluster
comes on when the
tow/haul mode is on.Tow/Haul is a feature that assists when pulling a heavy
trailer or a large or heavy load. See
Tow/Haul Mode
on
page 3‑34for more information.
Tow/Haul is designed to be most effective when the
vehicle and trailer combined weight is at least
75 percent of the vehicle's Gross Combined Weight
Rating (GCWR). See “Weight of the Trailer” earlier in
the section. Tow/Haul is most useful under the following
driving conditions:
.When pulling a heavy trailer or a large or heavy
load through rolling terrain.
.When pulling a heavy trailer or a large or heavy
load in stop and go traffic.
.When pulling a heavy trailer or a large or heavy
load in busy parking lots where improved low
speed control of the vehicle is desired.
Operating the vehicle in Tow/Haul when lightly loaded
or with no trailer at all will not cause damage. However,
there is no benefit to the selection of Tow/Haul when the
vehicle is unloaded. Such a selection when unloaded
may result in unpleasant engine and transmission
driving characteristics and reduced fuel economy.
Tow/Haul is recommended only when pulling a heavy
trailer or a large or heavy load.
5-48

Driving with a Trailer
{WARNING:
When towing a trailer, exhaust gases may collect
at the rear of the vehicle and enter if the liftgate,
trunk/hatch, or rear-most window is open.
Engine exhaust contains carbon monoxide (CO)
which cannot be seen or smelled. It can cause
unconsciousness and even death.
To maximize safety when towing a trailer:
.Have the exhaust system inspected for leaks
and make necessary repairs before starting
a trip.
.Never drive with the liftgate, trunk/hatch,
or rear-most window open.(Continued)
WARNING: (Continued)
.Fully open the air outlets on or under the
instrument panel.
.Adjust the Climate Control system to a setting
that brings in only outside air and set the fan
speed to the highest setting. See Climate
Control System in the Index.
For more information about carbon monoxide, see
Engine Exhaust on page 3‑40.
Towing a trailer requires a certain amount of
experience. The combination you are driving is longer
and not as responsive as the vehicle itself. Get
acquainted with the handling and braking of the rig
before setting out for the open road.
Before starting, check all trailer hitch parts and
attachments, safety chains, electrical connectors,
lamps, tires and mirrors. If the trailer has electric
brakes, start the combination moving and then apply the
trailer brake controller by hand to be sure the
brakes work.
During the trip, check occasionally to be sure that the
load is secure and the lamps and any trailer brakes
still work.
5-56

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