engine GMC YUKON XL 2010 Owners Manual

Four-Wheel Drive Vehicles with a Two
Speed Automatic Transfer Case
Use the following procedure to dinghy tow a four-wheel
drive vehicle with a two speed automatic transfer case:1. Position the vehicle being towed behind the tow vehicle and shift the transmission to P (Park).
2. Turn the engine off and firmly set the parking brake.
3. Securely attach the vehicle being towed to the tow vehicle.
{WARNING:
Shifting a four-wheel-drive vehicle's transfer case
into N (Neutral) can cause the vehicle to roll even
if the transmission is in P (Park). The driver or
others could be injured. Make sure the parking
brake is firmly set before the transfer case is
shifted to N (Neutral).
4. Shift the transfer case to N (Neutral). See “Shifting
into Neutral” under“Four-Wheel Drive” for the
proper procedure to select the Neutral position
for the vehicle.
5. Release the parking brake only after the vehicle being towed is firmly attached to the towing
vehicle.
6. Turn the ignition to LOCK/OFF and remove the key —the steering wheel will still turn.
After towing, see “Shifting Out of Neutral” under
“Four-Wheel Drive” for the proper procedure to take
the vehicle out of the Neutral position.
5-43

Towing a Trailer
If the vehicle has a two–mode hybrid engine, see the
Two–mode Hybrid manual for more information.
Do not tow a trailer during break‐in. SeeNew Vehicle
Break-In
on page 3‑27for more information.
{WARNING:
The driver can lose control when pulling a trailer if
the correct equipment is not used or the vehicle is
not driven properly. For example, if the trailer is
too heavy, the brakes may not work well —or
even at all. The driver and passengers could
be seriously injured. The vehicle may also be
damaged; the resulting repairs would not be
covered by the vehicle warranty. Pull a trailer only
if all the steps in this section have been followed.
Ask your dealer for advice and information about
towing a trailer with the vehicle. Notice:
Pulling a trailer improperly can damage
the vehicle and result in costly repairs not covered
by the vehicle warranty. To pull a trailer correctly,
follow the advice in this section and see your dealer
for important information about towing a trailer with
the vehicle.
To identify the trailering capacity of the vehicle, read the
information in “Weight of the Trailer” that appears later
in this section.
Trailering is different than just driving the vehicle
by itself. Trailering means changes in handling,
acceleration, braking, durability and fuel economy.
Successful, safe trailering takes correct equipment,
and it has to be used properly.
The following information has many time-tested,
important trailering tips and safety rules. Many of
these are important for your safety and that of your
passengers. So please read this section carefully
before pulling a trailer.
5-49

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 3‑60for 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
Weight of the Trailer
How heavy can a trailer safely be?
It depends on how the rig is used. Speed, altitude,
road grades, outside temperature and how much the
vehicle is used to pull a trailer are all important. It can
depend on any special equipment on the vehicle, and
the amount of tongue weight the vehicle can carry.
See
“Weight of the Trailer Tongue” later in this section
for more information.
Trailer weight rating (TWR) is calculated assuming the
tow vehicle has only the driver but all required trailering
equipment. Weight of additional optional equipment,
passengers and cargo in the tow vehicle must be
subtracted from the trailer weight rating.
Use the following chart to determine how much the
vehicle can weigh, based upon the vehicle model and
options.
5-50

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 3‑39for 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.
5-56

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.
.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 3‑52. 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.
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.
5-64

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 3‑39.
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 6‑36.
5-65

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. If the vehicle is four-wheel-drive and has a two-speed transfer case, be sure the transfer
case is in a drive gear and not in N (Neutral).
6. Release the brake pedal.
{WARNING:
It can be dangerous to get out of the vehicle if the
shift lever is not fully in P (Park) with the parking
brake firmly set. The vehicle can roll.
If the engine has been left running, the vehicle
can move suddenly. You or others could be
injured. To be sure the vehicle will not move,
even when on fairly level ground, use the steps
that follow.
Always put the shift lever fully in P (Park) with the
parking brake firmly set.
If the transfer case on a four-wheel-drive vehicle
is in N (Neutral), the vehicle will be free to roll,
even if the shift lever is in P (Park). Be sure the
transfer case is in a drive gear —not in
N (Neutral).
5-66

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 thechocks.
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.
Trailer Wiring Harness
The vehicle is equipped with the following wiring
harnesses for towing a trailer.
Basic Trailer Wiring
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to the
vehicle's frame. The harness connector can be plugged
into a seven-pin universal heavy-duty trailer connector
available through your dealer.
The seven-wire harness contains the following trailer
circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn Signal
.Brown: Taillamps
.White: Ground
.Light Green: Back-up Lamps
.Red: Battery Feed*
.Dark Blue: Trailer Brake*
*The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your dealer
or a qualified service center.
5-67

Section 6 Service and Appearance Care
Service. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
Accessories and Modifications . . . . . . . . . . . . . . . . . . 6-4
California Proposition 65 Warning . . . . . . . . . . . . . . . 6-5
California Perchlorate Materials Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-5
Doing Your Own Service Work . . . . . . . . . . . . . . . . . . 6-5
Adding Equipment to the Outside of the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-6
Gasoline Octane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
Gasoline Specifications . . . . . . . . . . . . . . . . . . . . . . . . . 6-7
California Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Additives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-8
Fuel E85 (85% Ethanol) . . . . . . . . . . . . . . . . . . . . . . . . . 6-9
Fuels in Foreign Countries . . . . . . . . . . . . . . . . . . . . . 6-10
Filling the Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-11
Filling a Portable Fuel Container . . . . . . . . . . . . . . . 6-13
Checking Things Under the Hood . . . . . . . . . . . . . . .6-14
Hood Release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-14
Engine Compartment Overview . . . . . . . . . . . . . . . . 6-16
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-18
Engine Oil Life System . . . . . . . . . . . . . . . . . . . . . . . . 6-20
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . . . . . . . . . 6-22
Automatic Transmission Fluid (4-Speed Transmission) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-24 Automatic Transmission Fluid (6-Speed
Transmission) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-27
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-30
Engine Coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-32
Engine Overheating . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-36
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Engine Fan Noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-39
Power Steering Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 6-40
Windshield Washer Fluid . . . . . . . . . . . . . . . . . . . . . . 6-41
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-42
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-45
Jump Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-46
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-51
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-52
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-53
Headlamp Aiming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-55
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
Taillamps, Turn Signal, Stoplamps and Back-up Lamps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-58
License Plate Lamp . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Replacement Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-60
Windshield Wiper Blade Replacement . . . . . . . . . . .6-61
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
If this vehicle is a Two‐mode Hybrid, see the Two‐mode
Hybrid manual for more information.
{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.
6-5