cooling GMC YUKON XL 2010 User Guide

Driving in Water
{WARNING:
Driving through rushing water can be dangerous.
Deep water can sweep your vehicle downstream
and you and your passengers could drown. If it
is only shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Do not drive
through rushing water.
Heavy rain can mean flash flooding, and flood waters
demand extreme caution.
Find out how deep the water is before driving through it.
Do not try it if it is deep enough to cover the wheel
hubs, axles, or exhaust pipe —you probably will not get
through. Deep water can damage the axle and other
vehicle parts.
If the water is not too deep, drive slowly through it.
At faster speeds, water splashes on the ignition system
and the vehicle can stall. Stalling can also occur if you get the tailpipe under water. If the tailpipe is under
water, you will never be able to start the engine.
When going through water, remember that when
the brakes get wet, it might take longer to stop.
See
Driving in Rain and on Wet Roads on page 5‑24.After Off-Road Driving
Remove any brush or debris that has collected
on the underbody, chassis, or under the hood.
These accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires, and exhaust system
for damage and check the fuel lines and cooling system
for any leakage.
The vehicle requires more frequent service due to
off-road use. Refer to the Maintenance Schedule for
additional information.
5-23

Highway Hypnosis
Always be alert and pay attention to your surroundings
while driving. If you become tired or sleepy, find a safe
place to park your vehicle and rest.
Other driving tips include:
.Keep the vehicle well ventilated.
.Keep interior temperature cool.
.Keep your eyes moving—scan the road ahead
and to the sides.
.Check the rearview mirror and vehicle instruments
often.
Hill and Mountain Roads
Driving on steep hills or through mountains is different
than driving on flat or rolling terrain. Tips for driving in
these conditions include:
.Keep the vehicle serviced and in good shape.
.Check all fluid levels and brakes, tires, cooling
system, and transmission.
.Going down steep or long hills, shift to a
lower gear.
{WARNING:
If you do not shift down, the brakes could get so
hot that they would not work well. You would then
have poor braking or even none going down a hill.
You could crash. Shift down to let the engine
assist the brakes on a steep downhill slope.
5-26

VehicleAxle Ratio Maximum Trailer Weight GCWR*
1500 Series 2WD Short Wheel Base
5.3L V8 3.08 5,400 lbs (2 449 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 5,900 lbs (2 676 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 8,400 lbs (3 810 kg) 14,000 lbs (6 350 kg)
1500 Series 2WD Long Wheel Base
5.3L V8 3.08 5,100 lbs (2 313 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 5,600 lbs (2 540 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
6.2L V8 3.42 8,100 lbs (3 674 kg) 14,000 lbs (6 350 kg)
1500 Series 4WD Short Wheel Base 5.3L V8 3.08 5,200 lbs (2 359 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 5,700 lbs (2 586 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 8,200 lbs (3 720 kg) 14,000 lbs (6 350 kg)
5-51

VehicleAxle Ratio Maximum Trailer Weight GCWR*
1500 Series 4WD Long Wheel Base
5.3L V8 3.08 5,000 lbs (2 268 kg) 11,000 lbs (4 990 kg)
5.3L V8 3.42 5,400 lbs (2 449 kg) 11,500 lbs (5 216 kg)
5.3L V8 K5L HD Cooling Pkg 3.42 7,900 lbs (3 583 kg) 14,000 lbs (6 350 kg)
6.2L V8 3.42 7,900 lbs (3 583 kg) 14,000 lbs (6 350 kg)
2500 Series 2WD Long Wheel Base 6.0L V8 3.73 9,600 lbs (4 355 kg) 16,000 lbs (7 257 kg)
2500 Series 4WD Long Wheel Base 6.0L V8 3.73 9,300 lbs (4 218 kg) 16,000 lbs (7 257 kg)
*The Gross Combination Weight Rating (GCWR) is the total allowable weight of the completely loaded vehicle and
trailer including any passengers, cargo, equipment and conversions. The GCWR for the vehicle should not be
exceeded.
Ask your dealer for trailering information or advice,
or write us at our Customer Assistance Offices.
See Customer Assistance Offices
on page 8‑6for
more information.
5-52

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

A.Engine Air Cleaner/Filter on page 6‑22.
B. Coolant Surge Tank and Pressure Cap. See Cooling System on page 6‑30.
C. Remote Positive (+) Terminal. See Jump Starting
on page 6‑46.
D. Battery on page 6‑45.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
under Engine Oil on page 6‑18.
F. Automatic Transmission Dipstick. See “Checking
the Fluid Level” underAutomatic Transmission
Fluid (4-Speed Transmission)
on page 6‑24or Automatic Transmission Fluid (6-Speed
Transmission) on page 6‑27.
G. Remote Negative (−) Terminal (Out of View). See Jump Starting on page 6‑46. H. Engine Oil Dipstick (Out of View). See
“Checking
Engine Oil” underEngine Oil on page 6‑18.
I. Engine Cooling Fan. See Cooling System
on
page 6‑30.
J. Power Steering Fluid Reservoir. See Power
Steering Fluid on page 6‑40.
K. Brake Master Cylinder Reservoir. See “Brake
Fluid” under Brakes on page 6‑42.
L. Underhood Fuse Block on page 6‑122.
M. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on
page 6‑41.
6-17

5. Safe operating level is within the HOT cross hatchband on the dipstick. If the fluid level is not within
the HOT band, and the transmission temperature
is between 71°C and 93°C (160°F and 200°F), add
or drain fluid as necessary to bring the level into
the HOT band. If the fluid level is low, add only
enough fluid to bring the level into the HOT band.
It does not take much fluid, generally less than
0.5 Liter (1 Pint). Do not overfill.
6. If the fluid level is in the acceptable range, push the dipstick back in all the way, then flip the handle
down to lock the dipstick in place.
Consistency of Readings
Always check the fluid level at least twice using
the procedure described previously. Consistency
(repeatable readings) is important to maintaining proper
fluid level. If readings are still inconsistent, contact your
dealer.
Cooling System
If the vehicle is a Two-mode Hybrid, see the Two-mode
Hybrid manual for more information.
The cooling system allows the engine to maintain the
correct working temperature.
6-30

5.3L Engine shown, 6.0L and 6.2L Engine similar
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.
Do not run the engine if there is a leak. If you run
the engine, it could lose all coolant. That could
cause an engine fire, and you could be burned.
Get any leak fixed before you drive the vehicle.
Notice: Using coolant other than DEX-COOL
®can
cause premature engine, heater core, or radiator
corrosion. In addition, the engine coolant could
require changing sooner, at 50 000 km (30,000 miles)
or 24 months, whichever occurs first. Any repairs
would not be covered by the vehicle warranty.
Always use DEX-COOL
®(silicate-free) coolant in
the vehicle.
6-31

Engine Coolant
The cooling system in the vehicle is filled with
DEX-COOL®engine coolant. This coolant is designed
to remain in the vehicle for five years or 150,000 miles
(240 000 km), whichever occurs first.
The following explains the cooling system and how
to check and add coolant when it is low. If there is
a problem with engine overheating, see Engine
Overheating on page 6‑36.
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.
6-32