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Driving and Operating 219
Make wider turns than normal when towing,
so trailer will not go over soft shoulders,
over curbs, or strike road signs, trees,
or other objects. Always signal turns well in
advance. Do not steer or brake suddenly.
Driving on Grades
Reduce speed and shift to a lower gear
before starting down a long or steep
downhill grade. If the transmission is not
shifted down, the brakes may overheat and
result in reduced braking efficiency.
The vehicle 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.
When towing at higher altitudes, engine
coolant will boil at a lower temperature
than at lower altitudes. If the engine is
turned off immediately after towing at high
altitude on steep uphill grades, the vehicle
could show signs similar to engine
overheating. To avoid this, let the engine
run, preferably on level ground, with the
transmission in P (Park) for a few minutes
before turning the engine off. If the
overheat warning comes on, seeEngine
Overheating 0247.
Parking on Hills
{Warning
To prevent serious injury or death,
always park your vehicle and trailer on a
level surface when possible.
When parking your vehicle and your trailer
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, gradually release the brake pedal to
allow the chocks to absorb the load of
the trailer.
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.
.Start the engine.
.Shift into a gear.
.Release the parking brake. 2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of
the chocks.
4. Stop and have someone pick up and store the chocks.
Launching and Retrieving a Boat
Backing the Trailer into the Water
{Warning
.Have all passengers get out of the
vehicle before backing onto the sloped
part of the ramp. Lower the driver and
passenger side windows before
backing onto the ramp. This will
provide a means of escape in the
unlikely event the vehicle slides into
the water.
.If the boat launch surface is slippery,
have the driver remain in the vehicle
with the brake pedal applied while the
boat is being launched. The boat
launch can be especially slippery at
low tide when part of the ramp was
previously submerged at high tide. Do
not back onto the ramp to launch the
boat if you are not sure the vehicle
can maintain traction.
(Continued)

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220 Driving and Operating
Warning (Continued)
.Do not move the vehicle if someone is
in the path of the trailer. Some parts
of the trailer might be underwater and
not visible to people who are assisting
in launching the boat.
Disconnect the wiring to the trailer before
backing the trailer into the water to prevent
damage to the electrical circuits on the
trailer. Reconnect the wiring to the trailer
after removing the trailer from the water.
If the trailer has electric brakes that can
function when the trailer is submerged, it
might help to leave the electrical trailer
connector attached to maintain trailer brake
functionality while on the boat ramp.
To back the trailer into the water: 1. If equipped, place the vehicle in four-wheel-drive high.
2. Slowly back down the boat ramp until the boat is floating, but no further than
necessary.
3. Press and hold the brake pedal, but do not shift into P (Park) yet.
4. Have someone place chocks under the front wheels of the vehicle. 5. Gradually release the brake pedal to
allow 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 of the water: 1. Press and hold the brake pedals.
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 0310. It is especially important to
check the automatic transmission fluid,
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 0247.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.

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Driving and Operating 227
Turn Signals When Towing a Trailer
When properly connected, the trailer turn
signals will illuminate to indicate the vehicle
is turning, changing lanes, or stopping.
When towing a trailer, the arrows on the
instrument cluster will illuminate even if the
trailer is not properly connected or the bulbs
are burned out.
Tow/Haul Mode
For instructions on how to enter Tow/Haul
Mode, seeTow/Haul Mode 0196.
Tow/Haul assists when pulling a heavy
trailer or a large or heavy load.
Tow/Haul Mode is designed to be most
effective when the vehicle and trailer
combined weight is at least 75% of the
vehicle's Gross Combined Weight Rating
(GCWR). See “Weight of the Trailer” under
Trailer Towing 0220.
Tow/Haul Mode is most useful when towing
a heavy trailer or carrying a large or
heavy load:
.through rolling terrain.
.in stop-and-go traffic.
.in busy parking lots. Operating the vehicle in Tow/Haul Mode
when lightly loaded or not towing will not
cause damage; however, it is not
recommended and may result in unpleasant
engine and transmission driving
characteristics and reduced fuel economy.
Integrated Trailer Brake Control System
The vehicle may have an Integrated Trailer
Brake Control (ITBC) system for use with
electric trailer brakes or most electric over
hydraulic trailer brake systems. These
instructions apply to both types of electric
trailer brakes.
This symbol is on the Trailer Brake Control
Panel on vehicles with an ITBC system. The
power output to the trailer brakes is
proportional to the amount of vehicle
braking. This available power output to the
trailer brakes can be adjusted to a wide
range of trailering situations.
The ITBC system is integrated with the
vehicle’s brake, antilock brake, and
StabiliTrak/Electronic Stability Control (ESC)
systems. In trailering conditions that cause
the vehicle’s antilock brake or StabiliTrak/
ESC systems to activate, power sent to the
trailer's brakes will be automatically
adjusted to minimize trailer wheel lock-up.
This does not imply that the trailer has
StabiliTrak/ESC.
If the vehicle’s brake, anti-lock brake,
or StabiliTrak/ESC systems are not
functioning properly, the ITBC system may
not function fully or at all. Make sure all of
these systems are fully operational to allow
the ITBC system to function properly.
The ITBC system is powered through the
vehicle's electrical system. Turning the
ignition off will also turn off the ITBC
system. The ITBC system is fully functional
only when the ignition is in ON/RUN.
{Warning
Connecting a trailer that has an air brake
system may result in reduced or
complete loss of trailer braking, including
increased stopping distance or trailer
instability which could result in serious
(Continued)

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Driving and Operating 229
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specific
trailering condition and it must be
readjusted anytime vehicle loading, trailer
loading, or road surface conditions change.
{Warning
Trailer brakes that are over-gained or
under-gained may not stop the vehicle
and the trailer as intended and can result
in a crash. Always follow the instructions
to set the Trailer Gain for the proper
trailer stopping performance.
To adjust Trailer Gain for each towing
condition: 1. Drive the vehicle with the trailer attached on a level road surface
representative of the towing condition
and free of traffic at about 32–40 km/h
(20–25 mph) and fully apply the Manual
Trailer Brake Apply Lever.
Adjusting Trailer Gain at speeds lower
than 32–40 km/h (20–25 mph) may
result in an incorrect gain setting. 2. Adjust the Trailer Gain, using the Trailer
Gain (+) or (-) adjustment buttons, to
just below the point of trailer wheel
lock-up, indicated by trailer wheel squeal
or tire smoke when a trailer wheel locks.
Trailer wheel lock-up may not occur if
towing a heavily loaded trailer. Adjust
the Trailer Gain to the highest allowable
setting for the towing condition.
3. Readjust Trailer Gain anytime vehicle loading, trailer loading, or road surface
conditions change or if trailer wheel
lock-up is noticed at any time while
towing.
Other ITBC-Related DIC Messages
TRAILER CONNECTED: This message will
briefly display when a trailer with electric
brakes is first connected to the vehicle. This
message will automatically turn off in about
10 seconds. This message can be
acknowledged before it automatically
turns off.
CHECK TRAILER WIRING: This message will
display if:
.The ITBC system first determines
connection to a trailer with electric brakes
and then the trailer harness becomes
disconnected from the vehicle. If the disconnect occurs while the vehicle
is stationary, this message will
automatically turn off in about
30 seconds. This message will also turn
off if it is acknowledged or if the trailer
harness is reconnected.
If the disconnect occurs while the vehicle
is moving, this message will continue
until the ignition is turned off. This
message will also turn off if it is
acknowledged or if the trailer harness is
reconnected.
.There is an electrical fault in the wiring to
the trailer brakes. This message will
continue as long as there is an electrical
fault in the trailer wiring. This message
will also turn off if it is acknowledged.
To determine whether the electrical fault is
on the vehicle side or trailer side of the
trailer wiring harness connection: 1. Disconnect the trailer wiring harness from the vehicle.
2. Turn the ignition off.
3. Wait 10 seconds, then turn the ignition back to RUN.
4. If the CHECK TRAILER WIRING message reappears, the electrical fault is on the
vehicle side.

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230 Driving and Operating
If the CHECK TRAILER WIRING message only
reappears when connecting the trailer wiring
harness to the vehicle, the electrical fault is
on the trailer side.
SERVICE TRAILER BRAKE SYSTEM: This
message will display when there is a
problem with the ITBC system. If this
message continues over multiple ignition
cycles, have the vehicle serviced.
If either the CHECK TRAILER WIRING or
SERVICE TRAILER BRAKE SYSTEM message
displays while driving, the ITBC system may
not be fully functional or may not function
at all. When traffic conditions allow,
carefully pull the vehicle over to the side of
the road and turn the ignition off. Check the
wiring connection to the trailer and turn the
ignition back on. If either of these messages
continues, either the vehicle or trailer needs
service.
A GM dealer may be able to diagnose and
repair problems with the trailer. However,
any diagnosis and repair of the trailer is not
covered under the vehicle warranty. Contact
your trailer dealer for assistance with trailer
repairs and trailer warranty information.Trailer Sway Control (TSC)
Vehicles with StabiliTrak/Electronic Stability
Control (ESC) have a Trailer Sway Control
(TSC) feature. Trailer sway is unintended
side-to-side motion of a trailer while towing.
If the vehicle is towing a trailer and the TSC
detects that sway is increasing, the vehicle
brakes are selectively applied at each wheel,
to help reduce excessive trailer sway.
If equipped with the Integrated Trailer Brake
Control (ITBC) system, and the trailer has an
electric brake system, StabiliTrak/ESC may
also apply the trailer brakes.
If TSC is enabled, the Traction Control
System (TCS)/StabiliTrak/ESC warning light
will flash on the instrument cluster. Reducevehicle speed by gradually removing your
foot from the accelerator. If trailer sway
continues, StabiliTrak/ESC can reduce engine
torque to help slow the vehicle. TSC will not
function if StabiliTrak/ESC is turned off. See
Traction Control/Electronic Stability Control
0
204.
{Warning
Trailer sway can result in a crash and in
serious injury or death, even if the
vehicle is equipped with TSC.
If the trailer begins to sway, reduce
vehicle speed by gradually removing your
foot from the accelerator. Then pull over
to check the trailer and vehicle to help
correct possible causes, including an
improperly or overloaded trailer,
unrestrained cargo, improper trailer hitch
configuration, or improperly inflated or
incorrect vehicle or trailer tires. See
Towing Equipment 0224 for trailer
ratings and hitch setup recommendations.

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Vehicle Care 233
Vehicle Care
General Information
General Information . . . . . . . . . . . . . . . . . . . 234
California Proposition 65 Warning . . . . . 234
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . . . . . . . . . . 234
Accessories and Modifications . . . . . . . . . 234
Vehicle Checks
Doing Your Own Service Work . . . . . . . . . 235
Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236
Engine Compartment Overview . . . . . . . . 237
Engine Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240
Engine Oil Life System . . . . . . . . . . . . . . . . 242
Automatic Transmission Fluid . . . . . . . . . 243
Engine Air Cleaner/Filter . . . . . . . . . . . . . . . 243
Cooling System . . . . . . . . . . . . . . . . . . . . . . . . 245
Engine Overheating . . . . . . . . . . . . . . . . . . . 247
Engine Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248
Washer Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Brake Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Battery - North America . . . . . . . . . . . . . . . 251
Four-Wheel Drive . . . . . . . . . . . . . . . . . . . . . . 252
Front Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252
Rear Axle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Starter Switch Check . . . . . . . . . . . . . . . . . . . 253
Automatic Transmission Shift Lock Control Function Check . . . . . . . . . . . . . . 253 Ignition Transmission Lock Check . . . . . . 253
Park Brake and P (Park) Mechanism
Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253
Wiper Blade Replacement . . . . . . . . . . . . . 254
Windshield Replacement . . . . . . . . . . . . . . 254
Gas Strut(s) . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
Headlamp Aiming
Front Headlamp Aiming . . . . . . . . . . . . . . . 255
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . . . . . . . . . . 256
Halogen Bulbs . . . . . . . . . . . . . . . . . . . . . . . . . 256
Headlamps, Front Turn Signal, Sidemarker, and Parking Lamps . . . . . . 256
Taillamps, Turn Signal, Sidemarker, Stoplamps, and Back-Up Lamps . . . . . . 257
Center High-Mounted Stoplamp (CHMSL) and Cargo Lamp . . . . . . . . . . . . 258
Electrical System
Electrical System Overload . . . . . . . . . . . . 259
Fuses and Circuit Breakers . . . . . . . . . . . . . 259
Engine Compartment Fuse Block . . . . . . 260
Instrument Panel Fuse Block . . . . . . . . . . 264
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
All-Season Tires . . . . . . . . . . . . . . . . . . . . . . . . 267
Winter Tires . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
All-Terrain Tires . . . . . . . . . . . . . . . . . . . . . . . 267
Tire Sidewall Labeling . . . . . . . . . . . . . . . . . 267 Tire Designations . . . . . . . . . . . . . . . . . . . . . . 269
Tire Terminology and Definitions . . . . . . 270
Tire Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 272
Tire Pressure Monitor System . . . . . . . . . 273
Tire Pressure Monitor Operation . . . . . . . 274
Tire Inspection . . . . . . . . . . . . . . . . . . . . . . . . 276
Tire Rotation . . . . . . . . . . . . . . . . . . . . . . . . . . 277
When It Is Time for New Tires . . . . . . . . 278
Buying New Tires . . . . . . . . . . . . . . . . . . . . . 278
Different Size Tires and Wheels . . . . . . . 279
Uniform Tire Quality Grading . . . . . . . . . 280
Wheel Alignment and Tire Balance . . . . 281
Wheel Replacement . . . . . . . . . . . . . . . . . . . 281
Tire Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
If a Tire Goes Flat . . . . . . . . . . . . . . . . . . . . . 282
Tire Changing . . . . . . . . . . . . . . . . . . . . . . . . . 284
Compact Spare Tire . . . . . . . . . . . . . . . . . . . 292
Full-Size Spare Tire . . . . . . . . . . . . . . . . . . . . 293
Jump Starting
Jump Starting - North America . . . . . . . . 294
Towing the Vehicle
Towing the Vehicle . . . . . . . . . . . . . . . . . . . 296
Recreational Vehicle Towing . . . . . . . . . . . 297
Appearance Care
Exterior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 300
Interior Care . . . . . . . . . . . . . . . . . . . . . . . . . . 304
Floor Mats . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307

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250 Vehicle Care
{Warning
The brake wear warning sound means
that soon the brakes will not work well.
That could lead to a crash. When the
brake wear warning sound is heard, have
the vehicle serviced.
Caution
Continuing to drive with worn-out brake
pads could result in costly brake repair.
Some driving conditions or climates can
cause a brake squeal when the brakes are
first applied or lightly applied. This does not
mean something is wrong with the brakes.
Properly torqued wheel nuts are necessary
to help prevent brake pulsation. When tires
are rotated, inspect brake pads for wear and
evenly tighten wheel nuts in the proper
sequence to torque specifications in
Capacities and Specifications 0324.
Brake linings should always be replaced as
complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not
return to normal height, or if there is a
rapid increase in pedal travel. This could be
a sign that brake service may be required.
Replacing Brake System Parts
Always replace brake system parts with
new, approved replacement parts. If this is
not done, the brakes may not work
properly. The braking performance expected
can change in many other ways if the
wrong replacement brake parts are installed
or parts are improperly installed.
Brake Fluid
The brake master cylinder reservoir is filled
with GM approved DOT 3 brake fluid as
indicated on the reservoir cap. See Engine
Compartment Overview 0237 for the
location of the reservoir. Checking Brake Fluid
With the vehicle in P (Park) on a level
surface, the brake fluid level should be
between the minimum and maximum marks
on the brake fluid reservoir.
There are only two reasons why the brake
fluid level in the reservoir may go down:
.Normal brake lining wear. When new
linings are installed, the fluid level goes
back up.
.A fluid leak in the brake hydraulic system.
Have the brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid reservoir cap
and the area around the cap before
removing it.
Do not top off the brake fluid. Adding fluid
does not correct a leak. If fluid is added
when the linings are worn, there will be too
much fluid when new brake linings are
installed. Add or remove fluid, as necessary,
only when work is done on the brake
hydraulic system.

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252 Vehicle Care
Infrequent Usage: Remove the black,
negative (−) cable from the battery to keep
the battery from running down.
Extended Storage: Remove the black,
negative (−) cable from the battery or use a
battery trickle charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer toMaintenance Schedule 0310 to
determine when to check the lubricant. How to Check Lubricant
Automatic Transfer Case
1. Drain Plug
2. Fill Plug
To get an accurate reading, the vehicle
should be on a level surface.
If the level is below the bottom of the fill
plug (2) hole, located on the transfer case,
some lubricant will need to be added. Add
enough lubricant to raise the level to the
bottom of the fill plug (2) hole. Use care not
to overtighten the plug.When to Change Lubricant
Refer to
Maintenance Schedule 0310 to
determine how often to change the
lubricant.
What to Use
Refer to Recommended Fluids and Lubricants
0 319 to determine what kind of lubricant
to use.
Front Axle
When to Check Lubricant
It is not necessary to regularly check the
front axle fluid unless a leak is suspected or
an unusual noise is heard. A fluid loss could
indicate a problem. Have it inspected and
repaired. This service can be complex. See
your dealer.
Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced.