
Driving and Operating 9-49
When towing at high altitude on
steep uphill grades, 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 transmission in P (Park) for
a few minutes before turning the
engine off. If the overheat warning
comes on, seeEngine Overheating
on page 10‑18.
On a long uphill grade, shift down
and reduce the vehicle speed to
around 88 km/h (55 mph) to reduce
the possibility of the engine and the
transmission overheating.
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 brake pedal
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 while you:
.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.

9-50 Driving and Operating
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. Inspect these before
and during the trip.
Check periodically to see that all
hitch nuts and bolts are tight.
Engine Cooling When Trailer
Towing
The cooling system may temporarily
overheat during severe operating
conditions. SeeEngine Overheating
on page 10‑18.
Trailer Towing
Three important considerations
have to do with weight:
.The weight of the trailer
.The weight of the trailer tongue
.The total weight on the vehicle's
tires
Weight of the Trailer
How heavy can a trailer safely be?
Speed, altitude, road grades,
outside temperature, special
equipment, and the amount of
tongue weight the vehicle can carry
must be considered. See “Weight of
the Trailer Tongue” later in this
section for more information.
Maximum trailer weight is calculated
assuming only the driver is in the
tow vehicle and it has all the
required trailering equipment.
The weight of additional optional
equipment, passengers and cargo in
the tow vehicle must be subtracted
from the maximum trailer weight.

9-54 Driving and Operating
Weight-Distributing Hitches and
Weight Carrying Hitches
A. Body-to-Ground Distance
B. Front of Vehicle
When using a weight-distributing
hitch, the hitch must be adjusted so
that the distance (A) remains the
same both before and after coupling
the trailer to the tow vehicle.
Safety Chains
Always attach chains between the
vehicle and the trailer. Cross the
safety chains under the tongue of
the trailer to help prevent the tongue
from contacting the road if it
becomes separated from the hitch.
Always leave just enough slack so
the rig can turn. Never allow safety
chains to drag on the ground.
Trailer Brakes
A loaded trailer that weighs more
than 450 kg (1,000 lbs) needs to
have its own brake system that is
adequate for the weight of the
trailer. Be sure to read and follow
the instructions for the trailer brakes
so they are installed, adjusted and
maintained properly.
Because the vehicle has antilock
brakes, do not try to tap into the
vehicle's hydraulic brake system.
If you do, both brake systems will
not work well, or at all.
Trailer Wiring Harness
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/retailer.
The seven-wire harness contains
the following trailer circuits:
.Yellow: Left Stop/Turn Signal
.Dark Green: Right Stop/Turn
Signal
.Brown: Taillamps
.Black: Ground
.Light Green: Back-up Lamps
.Red/Black: Battery Feed
.Dark Blue: Trailer Brake*
*The fuse for this circuit is installed
in the underhood electrical center,
but the wires are not connected.

Driving and Operating 9-55
They should be connected by your
dealer/retailer or a qualified service
center.
If the back-up lamp circuit is not
functional, contact your dealer/
retailer.
If a remote (non-vehicle) battery is
being charged, press the Tow/Haul
mode switch located on the center
console near the climate controls.
This will boost the vehicle system
voltage and properly charge the
battery. If the trailer is too light for
Tow/Haul mode, turn on the
headlamps (Non-HID only) as a
second way to boost the vehicle
system and charge the battery.Electric Trailer Brake Control
Wiring Provisions
These wiring provisions for an
electric trailer brake controller are
included with the vehicle as part of
the trailer wiring package. The
instrument panel contains blunt cut
wires behind the steering column for
the electric trailer brake controller.
The harness contains the following
wires:
.Red/Black: Power Supply
.White: Brake Switch Signal
.Gray: Illumination
.Dark Blue: Trailer Brake Signal
.Black: Ground
The electric trailer brake controller
should be installed by your dealer/
retailer or a qualified service center.
Conversions and
Add-Ons
Add-On Electrical
Equipment
Notice: Do not add anything
electrical to the vehicle unless
you check with your dealer/
retailer first. Some electrical
equipment can damage the
vehicle and the damage would
not be covered by the vehicle's
warranty. Some add-on electrical
equipment can keep other
components from working as
they should.
Add-on equipment can drain the
vehicle 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
on page 3‑41and Adding
Equipment to the Airbag-Equipped
Vehicle on page 3‑42.

Vehicle Care 10-1
Vehicle Care
General Information
General Information . . . . . . . . . . 10-2
California Proposition65 Warning . . . . . . . . . . . . . . . . . 10-3
California Perchlorate Materials Requirements . . . . 10-3
Accessories and Modifications . . . . . . . . . . . . . . . 10-3
Vehicle Checks
Doing Your OwnService Work . . . . . . . . . . . . . . . 10-4
Hood . . . . . . . . . . . . . . . . . . . . . . . . 10-4
Engine Compartment Overview . . . . . . . . . . . . . . . . . . . 10-6
Engine Cover . . . . . . . . . . . . . . . . 10-7
Engine Oil . . . . . . . . . . . . . . . . . . . 10-8
Engine Oil Life System . . . . . 10-10
Automatic Transmission Fluid . . . . . . . . . . . . . . . . . . . . . . 10-11
Engine Air Cleaner/Filter . . . . 10-12
Cooling System . . . . . . . . . . . . 10-14
Engine Coolant . . . . . . . . . . . . . 10-14
Engine Overheating . . . . . . . . 10-18 Overheated Engine
Protection
Operating Mode . . . . . . . . . . . 10-20
Power Steering Fluid . . . . . . . 10-20
Washer Fluid . . . . . . . . . . . . . . . 10-21
Brakes . . . . . . . . . . . . . . . . . . . . . 10-22
Brake Fluid . . . . . . . . . . . . . . . . . 10-23
Battery . . . . . . . . . . . . . . . . . . . . . 10-25
All-Wheel Drive . . . . . . . . . . . . . 10-25
Starter Switch Check . . . . . . . 10-25
Automatic Transmission Shift Lock Control System
Check . . . . . . . . . . . . . . . . . . . . . 10-26
Ignition Transmission Lock Check . . . . . . . . . . . . . . . . . . . . . 10-26
Park Brake and P (Park) Mechanism Check . . . . . . . . 10-26
Wiper Blade Replacement . . . . . . . . . . . . . . 10-27
Windshield Replacement . . . 10-28
Headlamp Aiming
Headlamp Aiming . . . . . . . . . . 10-28
Bulb Replacement
Bulb Replacement . . . . . . . . . . 10-28
Halogen Bulbs . . . . . . . . . . . . . . 10-28
High Intensity Discharge (HID) Lighting . . . . . . . . . . . . . 10-29 Taillamps, Turn Signal,
Sidemarker, and
Stoplamps . . . . . . . . . . . . . . . . 10-29
License Plate Lamp . . . . . . . . 10-30
Replacement Bulbs . . . . . . . . . 10-30
Electrical System
High Voltage Devices and Wiring . . . . . . . . . . . . . . . . . . . . . 10-30
Electrical System Overload . . . . . . . . . . . . . . . . . . 10-31
Fuses and Circuit Breakers . . . . . . . . . . . . . . . . . . 10-31
Engine Compartment Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-31
Instrument Panel Fuse Block . . . . . . . . . . . . . . . . . . . . . 10-35
Wheels and Tires
Tires . . . . . . . . . . . . . . . . . . . . . . . . 10-37
Tire Sidewall Labeling . . . . . . 10-38
Tire Designations . . . . . . . . . . . 10-40
Tire Terminology and
Definitions . . . . . . . . . . . . . . . . 10-41
Tire Pressure . . . . . . . . . . . . . . . 10-44
Tire Pressure Monitor System . . . . . . . . . . . . . . . . . . . 10-45
Tire Pressure Monitor Operation . . . . . . . . . . . . . . . . . 10-46

Vehicle Care 10-3
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.
Accessories and
Modifications
Adding non-dealer/non-retailer
accessories to the vehicle can affect
vehicle performance and safety,
including such things as airbags,
braking, stability, ride and handling,
emissions systems, aerodynamics,
durability, and electronic systems
like antilock brakes, traction control,
and stability control. Some of these
accessories could even cause
malfunction or damage not covered
by the vehicle warranty.
Damage to vehicle components
resulting from the installation or use
of non-GM certified parts, including
control module modifications, are
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.GM Accessories are designed to
complement and function with other
systems on the vehicle. Your GM
dealer/retailer can accessorize the
vehicle using genuine GM
Accessories. When you go to your
GM dealer/retailer and ask for GM
Accessories, you will know that
GM-trained and supported service
technicians will perform the work
using genuine GM Accessories.
Also, see
Adding Equipment to the
Airbag-Equipped Vehicle
on
page 3‑42.

Vehicle Care 10-7
A. Radiator Pressure Cap. SeeCooling System on page 10‑14.
B. Engine Coolant Recovery Cap. See Cooling System
on
page 10‑14.
C. Remote Negative (−) Terminal. See Jump Starting
on
page 10‑81.
D. Engine Compartment Fuse
Block on page 10‑31.
E. Remote Positive (+) Terminal. See Jump Starting
on
page 10‑81.
F. Power Steering Reservoir and Cap (under engine cover). See
Power Steering Fluid
on
page 10‑20.
G. Engine Oil Fill Cap. See “When
to Add Engine Oil” underEngine
Oil on page 10‑8. H.
Engine Cover on page 10‑7.
I. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil on page 10‑8.
J. Automatic Transmission Fluid Dipstick. See “Checking the
Fluid Level” underAutomatic
Transmission Fluid
on
page 10‑11.
K. Brake Master Cylinder Reservoir. See “Brake Fluid”
under Brakes on page 10‑22.
L. Engine Air Cleaner/Filter
on
page 10‑12.
M. Windshield Washer Fluid Reservoir. See “Adding Washer
Fluid” under Washer Fluid
on
page 10‑21.
Engine Cover
A. Oil Fill Cap
B. Engine Cover
To remove:
1. Remove the oil fill cap (A).
2. Raise the engine cover (B) to release from the retainers.
3. Lift and remove the engine cover.
4. Reverse Steps 1 through 3 to reinstall engine cover.

10-22 Vehicle Care
Adding Washer Fluid
When the windshield washer fluid
reservoir is low, a WASHER FLUID
LOW ADD FLUID message will be
displayed on the Driver Information
Center (DIC). SeeWasher Fluid
Messages
on page 5‑39for more
information.
Open the cap with the washer
symbol on it. Add washer fluid until
the tank is full. See Engine
Compartment Overview
on
page 10‑6for reservoir location. Notice:
.When using concentrated
washer fluid, follow the
manufacturer's instructions
for adding water.
.Do not mix water with
ready-to-use washer fluid.
Water can cause the solution
to freeze and damage your
washer fluid tank and other
parts of the washer system.
Also, water does not clean as
well as washer fluid.
.Fill the washer fluid tank only
three-quarters full when it is
very cold. This allows for
fluid expansion if freezing
occurs, which could
damage the tank if it is
completely full.
.Do not use engine coolant
(antifreeze) in your
windshield washer. It can
damage the vehicle's
windshield washer system
and paint.
Brakes
This vehicle has disc brakes. Disc
brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{WARNING
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
an accident. When the brake
wear warning sound is heard,
have the vehicle serviced.
Notice: Continuing to drive with
worn-out brake pads could result
in costly brake repair.