2004 GMC ENVOY brake light

Trailer Wiring Harness
Your vehicle may be equipped with the seven-wire
trailer towing harness. This harness has a seven-pin
universal heavy-duty trailer connector that is attached to
a bracket on the hitch platform. The seven-wire
harness contains the following trailer circuits:
Yellow: Left Stop/Turn Signal
Dark Green: Right Stop/Turn Signal
Brown: Running Lamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed
Dark Blue: Electric Brakes
If you need to tow a light-duty trailer with a standard
four-way round pin connector, an adapter connector is
available from your dealer.
Your vehicle may also be equipped with wiring for an
electric trailer brake controller. These wires are located
inside the vehicle on the driver’s side under the
instrument panel. These wires should be connected to
an electric trailer brake controller by your dealer or
a qualied service center.
4-66

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 rmly).
{CAUTION:
The brake wear warning sound means that
soon your 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 rst 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 specications.
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.
5-41

Jump Starting
If your battery has run down, you may want to use
another vehicle and some jumper cables to start your
vehicle. But please use the following steps to do it
safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.
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 aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t 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 rmly 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.
If you have a four-wheel-drive vehicle, be sure the
transfer case is not in NEUTRAL.
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 accessory power outlets (if equipped).
5-43

(A) Light Truck (LT-Metric) Tire:The United States
version of a metric tire sizing system. The letter “LT” as
the rst two characters in the tire size means a light
truck tire engineered to standards set by the U. S. Tire
and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is “75,” as shown in item “C” of
the illustration, it would mean that the tire’s sidewall is
75% as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
“R” means radial ply construction; the letter “D” means
diagonal or bias ply construction; and the letter “B”
means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:The service description
indicates the load range and speed rating of a tire. The
load index can range from 1 to 279. Speed ratings
range from “A” to “Z”. The light truck tire size example
above shows dual or single tire congurations.Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning. Light Truck (LT-Metric) Tire
5-62

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
Headlamp
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up-Trailer Lamps
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7Rear Window Washer, Headlamp
Washer
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog LampsFuses Usage
12 Stop Lamp
13 Cigarette Lighter
14 Ignition Coils
15 Blank
16 TBC-Ignition 1
17 Crank
18 Air Bag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle Control
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
5-104

Fuses Usage
1Electrically-Controlled Air
Suspension
2Passenger’s Side High-Beam
Headlamp
3Passenger’s Side Low-Beam
Headlamp
4 Back-Up-Trailer Lamps
5Driver’s Side High-Beam
Headlamp
6Driver’s Side Low-Beam
Headlamp
7Rear Window Washer, Headlamp
Washer
8 Active Transfer Case
9 Windshield Washer
10 Powertrain Control Module B
11 Fog LampsFuses Usage
12 Stop Lamp
13 Cigarette Lighter
14 Ignition Coils
15 Canister Vent
16 TBC-Ignition 1
17 Crank
18 Air Bag
19 Trailer Electric Brake
20 Cooling Fan
21 Horn
22 Ignition E
23 Electronic Throttle Control
24Instrument Panel Cluster, Driver
Information Center
25Automatic Shift Lock Control
System
5-107

A
Accessory Inator...........................................5-73
Accessory Power Outlets.................................3-19
Adding a Snow Plow or Similar Equipment.........4-55
Adding Washer Fluid.......................................5-38
Additional Program Information........................... 7-9
Additives, Fuel................................................. 5-6
Add-On Electrical Equipment...........................5-100
Adjustable Throttle and Brake Pedal..................2-22
Adjusting the Speakers
(Balance/Fade)............................3-67, 3-78, 3-93
After Off-Road Driving.....................................4-28
Air Bag
Readiness Light..........................................3-35
Air Bag Systems.............................................1-51
How Does an Air Bag Restrain?....................1-58
Servicing Your Air Bag-Equipped Vehicle.........1-61
What Makes an Air Bag Inate?....................1-58
What Will You See After an Air Bag Inates? . . 1-59
When Should an Air Bag Inate?...................1-57
Where Are the Air Bags?..............................1-55
Air Cleaner/Filter, Engine.................................5-21
Airbag Sensing and Diagnostic Module (SDM)....7-10
All Overseas Locations...................................... 7-5
AM .............................................................3-117
Antenna, Fixed Mast......................................3-120
Antenna, XM™ Satellite Radio Antenna System . . . 3-120
Anti-lock Brake System..................................... 4-6Anti-Lock Brake, System Warning Light..............3-39
Appearance Care............................................5-91
Care of Safety Belts....................................5-94
Chemical Paint Spotting...............................5-98
Cleaning the Inside of Your Vehicle................5-92
Cleaning the Outside of Your Vehicle..............5-95
Finish Damage............................................5-97
Sheet Metal Damage...................................5-97
Underbody Maintenance...............................5-98
Vehicle Care/Appearance Materials................5-98
Weatherstrips..............................................5-94
Approaching a Hill..........................................4-20
Ashtrays........................................................3-20
Audio Output................................................3-112
Audio System(s).............................................3-63
Audio Steering Wheel Controls....................3-116
Care of Your Cassette Tape Player...............3-118
Care of Your CD and DVD Player................3-119
Care of Your CDs and DVDs.......................3-119
Chime Level Adjustment.............................3-120
Fixed Mast Antenna...................................3-120
Navigation/Radio System.............................3-103
Audio Systems
Radio Personalization.................................3-115
Audio System(s)
Radio with Cassette and CD.........................3-75
Radio with CD............................................3-64
Radio with Six-Disc CD................................3-90
1

Audio System(s) (cont.)
Rear Seat Audio (RSA)...............................3-114
Setting the Time..........................................3-63
Theft-Deterrent Feature...............................3-116
Understanding Radio Reception...................3-117
XM™ Satellite Radio Antenna System...........3-120
Automatic Headlamp System............................3-15
Automatic Transfer Case..................................2-27
Automatic Transmission
Fluid..........................................................5-22
Operation...................................................2-24
B
Backglass Wiper Blade Replacement.................5-56
Backing Up....................................................4-62
Battery..........................................................5-42
BATTERY NOT CHARGING.............................3-60
Battery Replacement......................................... 2-7
Battery Run-Down Protection............................3-19
Before Leaving on a Long Trip.........................4-35
Before You Drive...........................................3-104
Before You Go Off-Roading..............................4-15
Brake
Parking......................................................2-30
System Warning Light..................................3-38
Brake Adjustment............................................5-41
Brake Fluid....................................................5-39Brake Pedal, Throttle.......................................2-22
Brake Pedal Travel.........................................5-41
Brake Wear...................................................5-41
Brakes..........................................................5-39
Braking........................................................... 4-6
Braking in Emergencies..................................... 4-8
Break-In, New Vehicle.....................................2-19
Bulb Replacement...........................................5-52
Front Turn Signal and Sidemarker Lamps.......5-52
Halogen Bulbs............................................5-52
Headlamps.................................................5-52
Replacement Bulbs......................................5-54
Taillamps and Turn Signal Lamps..................5-52
Buying New Tires...........................................5-68
C
California Fuel.................................................. 5-5
Canada........................................................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-7
Capacities and Specications..........................5-115
Carbon Monoxide...................4-38, 4-55, 2-14, 2-34
Care of
Safety Belts................................................5-94
Your Cassette Tape Player..........................3-118
Your CD and DVD Player...........................3-119
Your CDs and DVDs..................................3-119
2