2004 GMC SIERRA DENALI Electrical

BATTERY NOT CHARGING
If the battery is not charging during operation, this
message will appear on the DIC. Driving with this
problem could drain your battery. Have the electrical
system checked as soon as possible. Pressing the
select button will acknowledge this message and clear it
from the DIC display.
BUCKLE SEATBELT
If your vehicle is equipped with the passenger sensing
system, this message reminds you to buckle the
driver's and/or passenger's seatbelt. See
Passenger
Sensing System on page 1-73. The message will come
on and a chime will sound when the ignition is in
RUN and the following conditions occur:
·The driver's seatbelt is unbuckled.
·The driver's seatbelt is unbuckled and the
passenger's seatbelt is unbuckled with the
passenger airbag enabled.
Press the select button to acknowledge this message
and clear it from the DIC display.
BUCKLE PASSENGER
If your vehicle is equipped with the passenger sensing
system, this message reminds you to buckle the
passenger's seatbelt. See
Passenger Sensing System
on page 1-73. This message will come on and a
chime will sound when the ignition is in RUN and the
driver's seatbelt is buckled and the passenger's seatbelt
is unbuckled with the passenger airbag enabled.
Press the select button to acknowledge this message
and clear it from the DIC display.
CHANGE ENGINE OIL
This message is displayed for 10 seconds at the start of
each ignition cycle when the engine oil needs to be
changed.
When you change the engine oil, be sure to reset the
CHANGE ENGINE OIL message. See
Engine Oil, When
to ChangeunderEngine Oil on page 5-11.
CARGO LAMP ON
If the cargo lamp is on, this message will appear on the
DIC and you will hear a chime. Turn off the vehicle
and check the liftgate. Restart the vehicle and check for
the message on the DIC display. Pressing the select
button will acknowledge this message and clear it from
the DIC display.
3-58

Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon
monoxide (CO) could come into your vehicle.
You can not see or smell CO. It can cause
unconsciousness or death. See
Engine
Exhaust on page 2-29
. To maximize your safety
when towing a trailer:
·Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
·Keep the rear-most windows closed.
·If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. See
Dual Automatic Climate
Control System on page 3-19.Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you'll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
Before you start, check all trailer hitch parts and
attachments, safety chains, electrical connector, lamps,
tires and mirror adjustment. If the trailer has electric
brakes, start your vehicle and trailer moving and then
apply the trailer brake controller by hand to be sure
the brakes are working. This lets you check your
electrical connection at the same time.
During your trip, check occasionally to be sure that the
load is secure, and that the lamps and any trailer
brakes are still working.
While towing a trailer or when exposed to long periods
of sunshine, the ¯oor of the truck bed may become
very warm. Avoid putting items in the truck bed
that might be affected by high ambient temperatures.
4-65

Trailer Wiring Harness
Your pickup is equipped with the eight-wire trailer
towing harness. This harness with a seven-pin universal
heavy-duty trailer connector is attached to a bracket
on the hitch platform.
The Center High-Mounted Stoplamp (CHMSL) wire is
tied next to the trailer wiring harness for use with a
trailer, slide-in camper or cap.The eight-wire harness contains the following trailer
circuits:
·Yellow: Left Stop/Turn Signal
·Dark Green: Right Stop/Turn Signal
·Brown: Taillamps
·White: Ground
·Light Green: Back-up Lamps
·Light Blue: Center High-Mounted
Stoplamp (CHMSL)
·Red: Battery Feed
·Dark Blue: Trailer Brake
If your trailer is equipped with electrical brakes, you can
get a jumper harness/electric trailer brake control
with a trailer battery feed fuse from your dealer. This
harness and fuse should be installed by your dealer or a
quali®ed service center.
If you need to tow a light-duty trailer with a standard
four-way round pin connector, you can also get an
adapter from your dealer.
4-69

Windshield Wiper Blade Replacement..............5-58
Tires..............................................................5-59
In¯ation - Tire Pressure.................................5-67
Tire Inspection and Rotation...........................5-68
When It Is Time for New Tires.......................5-69
Buying New Tires.........................................5-70
Uniform Tire Quality Grading..........................5-71
Wheel Alignment and Tire Balance..................5-72
Wheel Replacement......................................5-73
Tire Chains..................................................5-74
If a Tire Goes Flat........................................5-75
Changing a Flat Tire.....................................5-76
Spare Tire...................................................5-95
Appearance Care............................................5-96
Cleaning the Inside of Your Vehicle.................5-96
Care of Safety Belts......................................5-98
Weatherstrips...............................................5-98Cleaning the Outside of Your Vehicle..............5-99
Sheet Metal Damage...................................5-101
Finish Damage...........................................5-102
Underbody Maintenance...............................5-102
Chemical Paint Spotting...............................5-102
Vehicle Care/Appearance Materials................5-103
Vehicle Identi®cation.....................................5-104
Vehicle Identi®cation Number (VIN)................5-104
Service Parts Identi®cation Label...................5-104
Electrical System..........................................5-105
Windshield Wiper Fuses...............................5-105
Power Windows and Other Power Options......5-105
Fuses and Circuit Breakers..........................5-105
Capacities and Speci®cations........................5-114
Section 5 Service and Appearance Care
5-2

Jump Starting
If your battery (or batteries) has run down, you may
want to use another vehicle and some jumper cables to
start your vehicle. Be sure to follow the steps below
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 the automatic
transmission in PARK (P) before setting the parking
brake. If you have a four-wheel-drive vehicle, be
sure the transfer case is in a drive gear not in
NEUTRAL.
5-41

Notice:If the jumper cables are removed in the
wrong order, electrical shorting may occur and
damage the vehicle. The repairs would not be
covered by your warranty. Remove the jumper
cables in the correct order, making sure that the
cables do not touch each other or other metal.
A. Heavy, Unpainted Metal Engine Part or Remote
Negative Terminal
B. Good Battery or Remote Positive (+) and Remote
Negative (-) Terminals
C. Dead Battery or Remote Positive (+) TerminalTo disconnect the jumper cables from both vehicles do
the following:
1. Disconnect the black negative (-) cable from the
vehicle that had the bad battery.
2. Disconnect the black negative (-) cable from
vehicle with the good battery.
3. Disconnect the red positive (+) cable from the
vehicle with the good battery.
4. Disconnect the red positive (+) cable from the other
vehicle.
5. Return the positive (+) remote terminal cover to its
original position.
Jumper Cable Removal
5-45

A. Low-Beam Headlamp
B. High-Beam Headlamp
2. Pull the headlamp assembly out.
3. Unplug the electrical connector.
4. Turn the old bulb counterclockwise and remove it
from the headlamp assembly.
5. Put the new bulb into the assembly and turn it
clockwise until it is tight. Use care not to touch
the bulb with your ®ngers or hands.
6. Plug in the electrical connector.
7. Put the headlamp assembly back into the vehicle.
Install and tighten the two pins.
Front Turn Signal, Sidemarker and
Daytime Running Lamps
A. Sidemarker Lamp
B. Retainer Clip
C. Front Turn Signal Lamp
D. Daytime Running Lamp (DRL)
1. Remove the headlamp assembly as mentioned
previously.
5-50

Electrical System
Windshield Wiper Fuses
The windshield wiper motor is protected by an internal
circuit breaker and a fuse. If the motor overheats due to
heavy snow, etc., the wiper will stop until the motor
cools. If the overload is caused by some electrical
problem and not snow, etc., be sure to get it ®xed.
Power Windows and Other Power
Options
Circuit breakers protect the power windows and other
power accessories. When the current load is too heavy,
the circuit breaker opens and closes, protecting the
circuit until the problem is ®xed or goes away.
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses, circuit breakers
and fusible thermal links. This greatly reduces the
chance of ®res caused by electrical problems.
Look at the silver-colored band inside the fuse. If the
band is broken or melted, replace the fuse. Be sure you
replace a bad fuse with a new one of the identical
size and rating.
If you ever have a problem on the road and don't have
a spare fuse, you can borrow one that has the same
amperage. Just pick some feature of your vehicle
that you can get along without ± like the radio or
cigarette lighter ± and use its fuse, if it is the correct
amperage. Replace it as soon as you can.
5-105