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280 Driving and Operating
5. Gradually release the brake pedal toallow the chocks to absorb the load of
the trailer.
6. Reapply the brake pedal. Then, apply the parking brake and shift into P (Park).
7. Release the brake pedal.
Pulling the Trailer from the Water
To pull the trailer out of the water: 1. Press and hold the brake pedal.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the sloped part of the boat
ramp, the vehicle can be shifted from
four-wheel-drive high. Shift into the drive
mode that is appropriate for the road
conditions.Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0394. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically to see that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0321.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, and
durability. 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.
Read this section carefully before pulling a
trailer.

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306 Driving and Operating
If Tow/Haul Mode is off and this setting is
on for a Trailer Profile, each time the vehicle
is turned on, a reminder will appear in the
DIC to turn on Tow/Haul Mode when the
Trailer Profile is active.
If Tow/Haul Mode is on and this setting is
on for a Trailer Profile, the reminder will not
appear when the Trailer Profile is active.
Conversions and Add-Ons
Add-On Electrical Equipment
{Warning
The Data Link Connector (DLC) is used for
vehicle service and Emission Inspection/
Maintenance testing. SeeMalfunction
Indicator Lamp (Check Engine Light) 0122.
A device connected to the DLC —such as
an aftermarket fleet or driver-behavior
tracking device —may interfere with
vehicle systems. This could affect vehicle
operation and cause a crash. Such devices
may also access information stored in the
vehicle’s systems.
Caution
Some electrical equipment can damage
the vehicle or cause components to not
work and would not be covered by the
vehicle warranty. Always check with your
dealer before adding electrical equipment.
Add-on equipment can drain the vehicle's
12-volt battery, even if the vehicle is not
operating.
The vehicle has an airbag system. Before
attempting to add anything electrical to the
vehicle, see Servicing the Airbag-Equipped
Vehicle 073 and
Adding Equipment to the Airbag-Equipped
Vehicle 073.
For information on wiring auxiliary switches,
see www.gmupfitter.com or contact your
dealer.
Adding a Snow Plow or Similar
Equipment
Caution
Do not exceed 72 km/h (45 mph) with a
snow plow mounted to the vehicle. The
vehicle could overheat and be damaged.
Before installing a snow plow on the vehicle,
follow these guidelines:
Caution
If the vehicle does not have the snow
plow prep package, RPO VYU, adding a
plow can damage the vehicle, and the
repairs would not be covered by the
vehicle warranty. Unless the vehicle was
built to carry a snow plow, do not add
one to the vehicle. If the vehicle has RPO
VYU, then the payload the vehicle can
carry will be reduced when a snow plow
is installed. The vehicle can be damaged
if either the front or rear axle ratings or
the Gross Vehicle Weight Rating (GVWR)
are exceeded.

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Driving and Operating 307
The plow the vehicle can carry depends on
many things, such as:
.The options the vehicle came with, and
the weight of those options.
.The weight and number of passengers to
be carried.
.The weight of items added to the vehicle,
like a tool box or truck cap.
.The total weight of any additional cargo
to be carried.
To safely carry a snow plow on the vehicle:
.With a snow plow attached, the engine
coolant temperature gauge may show a
higher temperature than while driving
without one. The snow plow could block
the airflow to the radiator. This could be
more noticeable as vehicle speed
increases. At speeds above 72 km/h
(45 mph), this may cause the engine
coolant to overheat. Move or angle the
snow plow blade to allow increased
airflow to the radiator.
.To increase the airflow, move the snow
plow blade position.
.If driving more than 24 km/h (15 mph),
angle the plow blade position.
.Make sure the weight on the front and
rear axles does not exceed the axle rating
for each.
.Follow the snowplow manufacturer’s
recommendations for any rear ballast that
may be required. Rear ballast may be
required to ensure a proper front and rear
weight distribution ratio even though the
actual weight at the front axle may be
less than the front axle rating.
.The snowplow manufacturer or installer
can assist in determining the amount of
rear ballast required to ensure that the
vehicle with the attached snowplow does
not exceed the GVW rating, the front and
rear axle ratings, or the front and rear
weight distribution ratio (refer to the GM
Upfitter Manual).
Front axle reserve capacity is the difference
between the Front Gross Axle Weight
Rating (GAWR) and the front axle weight of
the vehicle with full fuel, passengers, and
any other cargo. This is the amount of
weight that can be added to the front axle
before reaching the Front GAWR. To calculate the amount of weight any front
accessory, such as a snow plow, is adding to
the front axle, use this formula:
(W x (A + W.B.)) /W.B.= Weight the accessory
is adding to the front axle.
Where:
IW = Weight of added accessory
IA = Distance that the accessory is in
front of the front axle
IW.B. = Vehicle Wheelbase
For example, adding a 318 kg (700 lb) snow
plow actually adds more than 318 kg (700 lb)
to the front axle. Using the formula, if the

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Vehicle Care 309
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 310
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 310
Accessories and Modifications . . . . . . . . . 310
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 311
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Engine Compartment Overview . . . . . . . . 313
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Engine Oil Life System . . . . . . . . . . . . . . . . . 316
Automatic Transmission Fluid . . . . . . . . . . 317
Engine Air Filter Life System . . . . . . . . . . . 317
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 318
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 319
Engine Overheating . . . . . . . . . . . . . . . . . . . . 321
Overheated Engine Protection Operating Mode . . . . . . . . . . . . . . . . . . . . . 323
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
Power Steering Fluid . . . . . . . . . . . . . . . . . . 323
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Brake Pad Life System . . . . . . . . . . . . . . . . . 325
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
Battery - North America . . . . . . . . . . . . . . . 327
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 329
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Noise Control System . . . . . . . . . . . . . . . . . 329
Automatic Transmission Shift Lock
Control Function Check (Mechanical
Shifter) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Park Brake and P (Park) Mechanism Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
Wiper Blade Replacement . . . . . . . . . . . . . . 331
Glass Replacement . . . . . . . . . . . . . . . . . . . . . 331
Windshield Replacement . . . . . . . . . . . . . . . 332
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 333
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 333
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 333
LED Lighting . . . . . . . . . . . . . . . . . . . . . . . . . . . 333
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 333
Taillamps, Turn Signal, Stoplamps, and Back-Up Lamps . . . . . . . . . . . . . . . . . . . . . . 334
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . 335
License Plate Lamp . . . . . . . . . . . . . . . . . . . . 335
Electrical System
Electrical System Overload . . . . . . . . . . . . . 335
Fuses and Circuit Breakers . . . . . . . . . . . . . 337
Engine Compartment Fuse Block . . . . . . . 337 Instrument Panel Fuse Block (Left) . . . . . 341
Instrument Panel Fuse Block (Right) . . . 342
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 345
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 346
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . 346
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 346
Tire Designations . . . . . . . . . . . . . . . . . . . . . . 347
Tire Terminology and Definitions . . . . . . 348
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Tire Pressure Monitor System . . . . . . . . . . 351
Tire Pressure Monitor Operation . . . . . . . 351
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 356
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 357
When It Is Time for New Tires . . . . . . . . 359
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 360
Different Size Tires and Wheels . . . . . . . . 361
Uniform Tire Quality Grading . . . . . . . . . . 361
Wheel Alignment and Tire Balance . . . . 362
Wheel Replacement . . . . . . . . . . . . . . . . . . . 362
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 364
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 365
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . . 375
Jump Starting
Jump Starting - North America . . . . . . . . 376

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Vehicle Care 317
The oil life system can also be reset as
follows:1. Display the oil life percentage on the DIC. See Driver Information Center (DIC)
(Base Level) 0131 or
Driver Information Center (DIC) (Uplevel)
0 133.
2. Fully press the accelerator pedal slowly three times within five seconds.
3. If the display changes to 100%, the system is reset.
If the vehicle has a CHANGE ENGINE OIL
SOON message and it comes back on when
the vehicle is started and/or the oil
life percentage is near 0%, the engine oil
life system has not been reset. Repeat the
procedure.
Automatic Transmission Fluid
When to Check and Change Automatic
Transmission Fluid
It is usually not necessary to check the
transmission fluid level. The only reason for
fluid loss is a transmission leak or
overheated transmission. This vehicle is not
equipped with a transmission fluid level
dipstick. There is a special procedure for
checking and changing the transmission fluid in these vehicles. Because this procedure is
difficult, this should be done at the dealer.
Contact the dealer for additional information
or the procedure can be found in the service
manual. See
Publication Ordering
Information 0413.
Caution
Use of the incorrect automatic
transmission fluid may damage the
vehicle, and the damage may not be
covered by the vehicle warranty. Always
use the correct automatic transmission
fluid. See Recommended Fluids and
Lubricants 0398.
Change the fluid and filter at the scheduled
maintenance intervals listed in Maintenance
Schedule 0394. Be sure to use the
transmission fluid listed in Recommended
Fluids and Lubricants 0398.
Engine Air Filter Life System
This feature provides the engine air filter’s
remaining life and best timing for a change.
The timing to change and engine air filter
depends on driving and environmental
conditions.
When to Change Engine Air Filter
When the Driver Information Center (DIC)
displays a message to replace the engine air
filter at the next oil change, follow this
timing.
When the DIC displays a message to replace
the engine air filter soon, replace the engine
air filter at the earliest convenience.
The system must be reset after the engine
air filter is changed.
If the DIC displays a message to check the
engine air filter system, see your dealer.
How to Reset Engine Air Filter Life
System
To reset:
1. Place the vehicle in P (Park).
2. Display the Air Filter Life on the DIC. See Driver Information Center (DIC) (Base
Level) 0131 or
Driver Information Center (DIC) (Uplevel)
0 133.
3. Press
Ton the steering wheel, or press
the trip odometer reset stem if the
vehicle does not have the DIC controls,
to move to the Reset/Disable display

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Vehicle Care 319
Caution
If the air cleaner/filter is off, dirt can
easily get into the engine, which could
damage it. Always have the air
cleaner/filter in place when driving.
Cooling System
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement.
The cooling system allows the engine to
maintain the correct working temperature.
{Warning
An underhood electric fan 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.
1. Engine Cooling Fan (Out of View)
2. Coolant Surge Tank and Pressure Cap
{Warning
Do not touch heater, radiator, a/c pipes
or hoses, or other engine parts. They can
be very hot and can burn you. Do not
run the engine if there is a leak; all
coolant could leak out. That could cause
an engine fire and can burn you. Fix any
leak before driving the vehicle.
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
5 years or 240 000 km (150,000 mi),
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, seeEngine Overheating 0321.
What to Use
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
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. This mixture:
.Gives freezing protection down to −37 °C
(−34 °F), outside temperature.
.Gives boiling protection up to 129 °C
(265 °F), engine temperature.

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320 Vehicle Care
.Protects against rust and corrosion.
.Will not damage aluminum parts.
.Helps keep the proper engine
temperature.
Caution
Do not use anything other than a mix of
DEX-COOL coolant that meets GM
Standard GMW3420 and clean, drinkable
water. Anything else can cause damage
to the engine cooling system and the
vehicle, which would not be covered by
the vehicle warranty.
Never dispose of engine coolant by putting
it in the trash, or by pouring it on the
ground, or into sewers, streams, or bodies of
water. Have the coolant changed by an
authorized service center, familiar with legal
requirements regarding used coolant
disposal. This will help protect the
environment and your health.
Checking Coolant
The coolant surge tank is in the engine
compartment on the driver side of the
vehicle. See Engine Compartment Overview
0 313. 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, wait until it
cools down. The coolant level should be at
or above the indicated mark. If it is not,
there may be a leak in the cooling system.
If coolant is visible but the coolant level is
not at or above the indicated mark, see the
following sections on how to add coolant to
the coolant surge tank following.
How to Add Coolant to the Coolant
Surge Tank
If the vehicle has a diesel engine, see
“Cooling System”
in the Duramax diesel
supplement for the proper coolant fill
procedure.
{Warning
Spilling coolant on hot engine parts can
burn you. Coolant contains ethylene
glycol and it will burn if the engine parts
are hot enough.
{Warning
Plain water, or other liquids such as
alcohol, can boil before the proper
coolant mixture will. With plain water or
the wrong mixture, the engine could get
too hot but there would not be an
overheat warning. The engine could catch
fire and you or others could be burned.

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Vehicle Care 321
{Warning
Steam and scalding liquids from a hot
cooling system are under pressure.
Turning the pressure cap, even a little,
can cause them to come out at high
speed and you could be burned. Never
turn the cap when the cooling system,
including the pressure cap, is hot. Wait
for the cooling system and pressure cap
to cool.
Caution
Failure to follow the specific coolant fill
procedure could cause the engine to
overheat and could cause system
damage. If coolant is not visible in the
surge tank, contact your dealer.
If no coolant is visible in the surge tank, add
coolant.
1. Remove the coolant surge tank pressure cap when the cooling system, including
the coolant surge tank pressure cap and
upper radiator hose, is no longer hot.
Turn the pressure cap slowly
counterclockwise about one full turn. If a
hiss is heard, wait for that to stop.
A hiss means there is still some
pressure left.
2. Keep turning the pressure cap slowly, and remove it.
3. Fill the coolant surge tank with the proper mixture to the full cold mark.
4. With the coolant surge tank pressure cap off, start the engine and let it run until
the engine coolant temperature gauge
indicates approximately 90 °C (195 °F).
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 indicated mark.
5. Replace the pressure cap tightly.
6. Verify coolant level after the engine is shut off and the coolant is cold.
If necessary, repeat coolant fill procedure
Steps 1–6.Caution
If the pressure cap is not tightly installed,
coolant loss and engine damage may
occur. Be sure the cap is properly and
tightly secured.
Engine Overheating
If the vehicle has the Duramax diesel
engine, see the Duramax diesel supplement.
Caution
Do not run the engine if there is a leak
in the engine cooling system. This can
cause a loss of all coolant and can
damage the system and vehicle. Have
any leaks fixed right away.
The vehicle has several indicators to warn of
engine overheating.
There is a coolant temperature gauge in the
vehicle's instrument cluster. See Engine
Coolant Temperature Gauge 0118.
In addition, there are ENGINE OVERHEATED
STOP ENGINE, ENGINE OVERHEATED IDLE
ENGINE, and ENGINE POWER IS REDUCED
messages in the Driver Information
Center (DIC).