Avoid needless heavy braking. Some people drive
in spurts — heavy acceleration followed by heavy
braking — rather than keeping pace with traffic.
This is a mistake. The brakes may not have time to
cool between hard stops. The brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic
following distances, you will eliminate a lot of
unnecessary braking. That means better braking
and longer brake life.
If your vehicle’s engine ever stops while you are
driving, brake normally but do not pump the
brakes. If you do, the pedal may get harder to
push down. If the engine stops, you will still have
some power brake assist. But you will use it
when you brake. Once the power assist is used
up, it may take longer to stop and the brake pedal
will be harder to push.
Adding non-GM accessories can affect your
vehicle’s performance. SeeAccessories and
Modi cations on page 286.Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System
(ABS), an advanced electronic braking system that
will help prevent a braking skid.
When you start your engine and begin to drive
away, ABS will check itself. You may hear a
momentary motor or clicking noise while this test
is going on. This is normal.
If there is a problem
with the ABS, this
warning light will stay
on. SeeAnti-Lock Brake
System Warning Light
on page 176.
233
Pressing and holding
the StabiliTrak®button
located on the
instrument panel for
more than five seconds
can turn off StabiliTrak
®
and part of the
traction control system.
For your safety, the system can only be disabled
when the vehicle speed is less than 20 mph
(32 km/h). You will hear three chimes and the
StabiliTrak
®not ready light will come on.
To turn on the StabiliTrak
®system, press the
StabiliTrak®button again. StabiliTrak®will
automatically turn back on when the vehicle speed
exceeds 20 mph (32 km/h). You will hear one chime
and the StabiliTrak
®not ready light will turn off.
When the StabiliTrak
®system has been turned off
you may still hear system noises as a result of
the brake-traction control coming on.It is recommended to leave the system on for
normal driving conditions, but it may be necessary
to turn the system off if your vehicle is stuck in
sand, mud, ice or snow, and you want to “rock”
your vehicle to attempt to free it. SeeIf Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 258.
StabiliTrak®System Operation
The StabiliTrak®system is normally on, except
when the system is initializing or has been
disabled with the StabiliTrak
®button. The
StabiliTrak®system will automatically activate to
assist the driver in maintaining vehicle directional
control in most driving conditions. When activated,
the StabiliTrak
®system may reduce engine
power to the wheels and apply braking to individual
wheels as necessary to assist the driver with
vehicle directional control. If your vehicle is
in cruise control when the system activates, the
StabiliTrak
®indicator light on the instrument panel
will flash, and the cruise control will automatically
disengage. When the StabiliTrak
®system is
no longer active, you may re-engage the cruise
control. SeeCruise Control on page 151.
237
The heavier the rain, the harder it is to see.
Even if your windshield wiper blades are in good
shape, a heavy rain can make it harder to see road
signs and traffic signals, pavement markings, the
edge of the road, and even people walking.
It is wise to keep your wiping equipment in good
shape and keep your windshield washer fluid
reservoir filled with washer fluid. Replace your
windshield wiper inserts when they show signs of
streaking or missing areas on the windshield, or
when strips of rubber start to separate from the
inserts.
{CAUTION:
Wet brakes can cause accidents. They
may not work as well in a quick stop and
may cause pulling to one side. You could
lose control of the vehicle.
After driving through a large puddle of
water or a car wash, apply your brake pedal
lightly until your brakes work normally.Driving too fast through large water puddles or
even going through some car washes can cause
problems, too. The water may affect your brakes.
Try to avoid puddles. But if you cannot, try to slow
down before you hit them.
Hydroplaning
Hydroplaning is dangerous. So much water can
build up under your tires that they can actually ride
on the water. This can happen if the road is wet
enough and you are going fast enough. When your
vehicle is hydroplaning, it has little or no contact
with the road.
Hydroplaning does not happen often. But it can
if your tires do not have much tread or if the
pressure in one or more is low. It can happen if
a lot of water is standing on the road. If you
can see reflections from trees, telephone poles, or
other vehicles, and raindrops dimple the water’s
surface, there could be hydroplaning.
Hydroplaning usually happens at higher speeds.
There just is not a hard and fast rule about
hydroplaning. The best advice is to slow down
when it is raining.
246
Maintenance When Trailer Towing
Your vehicle will need service more often when
you’re pulling a trailer. See the Maintenance
Schedule for more on this. Things that are
especially important in trailer operation are
automatic transmission fluid (don’t overfill), engine
oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual,
and the Index will help you find them quickly.
If you’re trailering, it’s a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and
bolts are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package
includes a seven-wire harness assembly at
the rear of the vehicle and a four-wire
harness assembly under the left hand side
of the instrument panel. The seven-wire
harness assembly is taped together and
located in a frame pocket at the driver side
rear left corner of the frame.The seven-wire harness includes a 30-amp feed
wire. Both harnesses come without connectors and
should be wired by a qualified electrical technician.
The technician can use the following color code
chart when connecting the wiring harness to
your trailer and trailer brake controller.
Seven-Wire Harness
•Light Green: Back-up lamps
•Brown: Parking lamps
•Yellow: Left stoplamp and turn signal
•Dark Green: Right stoplamp and turn signal
•Dark Blue: Use for electric trailer brakes
•Red/Black Stripe: Trailer accessory
•White (heavy gage): Ground wire
Four-Wire Harness (Trailer Brake Controller)
•Black: Ground
•Red/White Stripe: Fused Battery
•Dark Blue: Trailer Brake Feed
•Light Blue: Fused Stoplamp/CHMSL
282
Brake Wear
Your vehicle has four-wheel 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 may come and go or be heard all
the time your vehicle is moving, except when you
are pushing on the brake pedal firmly.
{CAUTION:
The brake wear warning sound means that
soon the brakes will not work well. That
could lead to an accident. When you hear
the brake wear warning sound, have your
vehicle serviced.
Notice:Continuing to drive with worn-out
brake pads could result in costly brake repair.Some driving conditions or climates may cause a
brake squeal when the brakes are first applied
or lightly applied. This does not mean something
is wrong with your 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 GM torque
specifications.
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 of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc
brakes adjust for wear.
322
Notice:Ignoring these steps could result in
costly damage to your vehicle that would
not be covered by your warranty.
Trying to start your vehicle by pushing or
pulling it will not work, and it could damage
your vehicle.
1. Check the other vehicle. It must have a
12-volt battery with a negative ground system.
Notice:If the other vehicle’s system is not a
12-volt system with a negative ground,
both vehicles can be damaged. Only use
vehicles with 12-volt systems with negative
grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper
cables can reach, but be sure the vehicles are
not touching each other. If they are, it could
cause a ground connection you do not
want. You would not be able to start your
vehicle, and the bad grounding could damage
the electrical systems.To avoid the possibility of the vehicles rolling,
set the parking brake firmly on both vehicles
involved in the jump start procedure. Put
an automatic transmission in PARK (P) or a
manual transmission in NEUTRAL before
setting the parking brake.
Notice:If you leave your radio or other
accessories on during the jump starting
procedure, they could be damaged. The repairs
would not be covered by your warranty.
Always turn off your radio and other
accessories when jump starting your vehicle.
3. Turn off the ignition on both vehicles.
Unplug unnecessary accessories plugged into
the cigarette lighter or the accessory power
outlet. Turn off the radio and all lamps that are
not needed. This will avoid sparks and help
save both batteries. And it could save
the radio!
325
Fuse Usage
18 Truck Body Control Module 2
19 Truck Body Control Module
20 Remote Function Actuator
21 Engine 2 (Gas), Spare (Diesel)
22 Ignition E
23 Engine 1
24Truck Body Control Module
Ignition 1
25 Spare (Gas), Fuel Heater (Diesel)
26 Inside Rearview Mirror
27 Crankcase
28Brake Transmission Shift
Interlock System
29 Auxiliary Power Outlets
30 Cigarette Lighter
31 Instrument Panel Cluster
32 Air ConditioningFuse Usage
33Spare (Gas), Engine Control
Module (Diesel)
34Canister Vent Solenoid (Gas), Rear
Fog Lamps (Diesel)
35Spare (Gas & LLY Diesel), Fan
Clutch (LMM Diesel)
36Brake Transmission Shift Interlock,
Vehicle Back-Up
37 Airbag
38Powertrain Control Module Ignition 1
(Gas), Engine Control Module,
Transmission Control Module, Glow
Plug Control Module Ignition 1
(Diesel)
39Oxygen Sensor B (Gas),
Spare (Diesel)
40Oxygen Sensor A (Gas),
Spare (Diesel)
41 Windshield Wipers
42 Right Headlamp - Low Beam
391
MaintenanceI— Use MaintenanceIif the
change engine oil light comes on within 10 months
since the vehicle was purchased or MaintenanceII
was performed.MaintenanceII— Use MaintenanceIIif the
previous service performed was MaintenanceI.
Always use MaintenanceIIwhenever the message
comes on 10 months or more since the last
service or if the message has not come on at all
for one year.
Scheduled Maintenance
Service MaintenanceIMaintenanceII
Change engine oil and filter. SeeEngine Oil (Gasoline Engine) on page 297.
Reset oil life system. SeeEngine Oil Life System (Gasoline Engine) on
page 300.An Emission Control Service.••
Lubricate chassis components.See footnote #.••
Visually check for any leaks or damage.See footnote (j).••
Inspect engine air cleaner filter. If necessary, replace filter. SeeEngine Air
Cleaner/Filter on page 302.See footnote (l).•
Rotate tires and check inflation pressures and wear. SeeTire Inspection and
Rotation on page 351and “Tire Wear Inspection” inAt Least Once a Month
on page 406.••
Inspect brake system.See footnote (a).••
400