2008 GMC SIERRA fuses

The theft-deterrent system will not activate if the doors
are locked with the vehicle’s key or the manual door
lock. It activates only if you use the power door
lock switch with the door open or the RKE transmitter.
You should also remember that you can start your
vehicle with the correct ignition key if the alarm has been
set off.
To avoid setting off the alarm by accident:
If you do not want to activate the theft-deterrent
system, the vehicle should be locked with the
door key after the doors are closed.
Always unlock a door with the RKE transmitter.
Unlocking a door any other way will set off the alarm
if the system has been armed.
If you set off the alarm by accident, press unlock on the
RKE transmitter or place the key in the ignition and
turn it to START to turn it off.
Testing the Alarm
To test the alarm:
1. From inside the vehicle, lower the driver’s window
and open the driver’s door.
2. Activate the system by locking the doors with the
RKE transmitter.
3. Get out of the vehicle, close the door and wait for
the security light to go out.
4. Then reach in through the window, unlock the door
with the manual door lock and open the door. This
should set off the alarm.
If the alarm does not sound when it should but the
headlamps ash, check to see if the horn works. The
horn fuse may be blown. To replace the fuse, seeFuses
and Circuit Breakers on page 5-123.
If the alarm does not sound or the headlamps do not
ash, see your dealer/retailer for service.
2-19

If the engine still does not start, and the key appears to
be undamaged, try another ignition key. At this time,
you may also want to check the fuse, seeFuses
and Circuit Breakers on page 5-123. If the engine still
does not start with the other key, your vehicle needs
service. If your vehicle does start, the rst key may be
faulty. See your dealer/retailer who can service the
PASS-Key
®III+ to have a new key made. In an
emergency, contact Roadside Assistance.
It is possible for the PASS-Key
®III+ decoder to learn
the transponder value of a new or replacement key. Up
to 10 keys may be programmed for the vehicle. The
following procedure is for programming additional keys
only. If all the currently programmed keys are lost or
do not operate, you must see your dealer/retailer
or a locksmith who can service PASS-Key
®III+ to have
keys made and programmed to the system.
See your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to get a new key blank that is cut
exactly as the ignition key that operates the system.To program the new additional key:
1. Verify that the new key has a
1stamped on it.
2. Insert the original, already programmed, key in the
ignition and start the engine. If the engine will not
start, see your dealer/retailer for service.
3. After the engine has started, turn the key to
LOCK/OFF, and remove the key.
4. Insert the new key to be programmed and turn it to
the ON/RUN position within ve seconds of turning
the ignition to the LOCK/OFF position in Step 3.
The security light will turn off once the key has been
programmed.
5. Repeat Steps 1 through 4 if additional keys are to
be programmed.
If you lose or damage your PASS-Key
®III+ key, see
your dealer/retailer or a locksmith who can service
PASS-Key
®III+ to have a new key made.
Do not leave the key or device that disarms or
deactivates the theft deterrent system in the vehicle.
2-21

Turn and Lane-Change Signals
The turn signal has two upward (for right) and two
downward (for left) positions. These positions allow
you to signal a turn or a lane change.
To signal a turn, move the lever all the way up or down.
When the turn is nished, the lever will return
automatically.
To signal a lane change, raise or lower the lever for
less than one second until the arrow starts to ash.
This will cause the turn signals to automatically
ash three times. It will ash six times if tow-haul mode
is active. Holding the turn signal lever for more than
one second will cause the turn signals to ash until you
release the lever. The lever will return by itself when
it is released.An arrow on the instrument
panel cluster will ash in
the direction of the
turn or lane change.
As you signal a turn or a lane change, if the arrows
ash more quickly than normal, a signal bulb may
be burned out and other drivers will not see your
turn signal.
If a bulb is burned out, replace it to help avoid an
accident. If the arrows do not go on at all when you
signal a turn, check for burned-out bulbs and a blown
fuse. SeeFuses and Circuit Breakers on page 5-123.
3-10

Certain power accessory plugs may not be compatible
to the accessory power outlet and could result in
blown vehicle or adapter fuses. If you experience a
problem, see your dealer/retailer for additional
information on the accessory power plugs.
The accessory power outlets are powered, even when
the ignition is in LOCK/OFF. Continuing to use
power outlets while the ignition is in LOCK/OFF may
cause the vehicle’s battery to run down.
Notice:Adding any electrical equipment to your
vehicle may damage it or keep other components
from working as they should. The repairs would not
be covered by your warranty. Do not use equipment
exceeding maximum amperage rating of 20
amperes. Check with your dealer/retailer before
adding electrical equipment.
When adding electrical equipment, be sure to follow the
proper installation instructions included with the
equipment.
Notice:Improper use of the power outlet can cause
damage not covered by your warranty. Do not
hang any type of accessory or accessory bracket
from the plug because the power outlets are
designed for accessory power plugs only.Ashtray(s) and Cigarette Lighter
Your vehicle may have a front ashtray located near the
center of the instrument panel. Pull on the door to
open it. The ashtray may have a cigarette lighter.
Notice:If you put papers, pins, or other ammable
items in the ashtray, hot cigarettes or other
smoking materials could ignite them and possibly
damage your vehicle. Never put ammable items in
the ashtray.
To remove the ashtray, open the door and pull the
ashtray bin toward you. To replace the ashtray, insert
the ashtray bin inside the ashtray door and press down
until it engages. To use the cigarette lighter, push it
in all the way, and let go. When it is ready for use, the
lighter pops back out.
Notice:Holding a cigarette lighter in while it is
heating does not let the lighter back away from the
heating element when it is hot. Damage from
overheating can occur to the lighter or heating
element, or a fuse could be blown. Do not hold a
cigarette lighter in while it is heating.
3-24

Heavy-DutyTrailer Wiring Harness
Package
For vehicles equipped with heavy duty trailering, the
harness is connected 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: Taillamps
White: Ground
Light Green: Back-up Lamps
Red: Battery Feed*
Dark Blue: Trailer Brake**The fuses for these two circuits are installed in the
underhood electrical center, but the wires are not
connected. They should be connected by your dealer or
a qualied service center. The fuse and wire for the
ITBC is factory installed and connected if the vehicle is
equipped with an ITBC. The fuse for the battery
feed is not required if your vehicle has an auxiliary
battery. If your vehicle does not have an auxiliary
battery, have your dealer or authorized service center
install the required fuse.
If you are charging a remote (non-vehicle) battery, press
the tow/haul mode button located at the end of the
shift lever. This will boost the vehicle system voltage and
properly charge the battery. If the trailer is too light for
tow/haul mode, you can turn on the headlamps as
a second way to boost the vehicle system and charge
the battery.
4-91

Windshield and Wiper Blades.......................5-117
Aluminum or Chrome-Plated
Wheels and Trim.....................................5-118
Tires.........................................................5-119
Sheet Metal Damage...................................5-119
Finish Damage...........................................5-119
Underbody Maintenance...............................5-119
Chemical Paint Spotting...............................5-120
Vehicle Care/Appearance Materials................5-120
Vehicle Identication.....................................5-121
Vehicle Identication Number (VIN)................5-121
Service Parts Identication Label...................5-122Electrical System..........................................5-122
Add-On Electrical Equipment.........................5-122
Windshield Wiper Fuses...............................5-123
Power Windows and Other Power Options......5-123
Fuses and Circuit Breakers..........................5-123
Instrument Panel Fuse Block........................5-124
Center Instrument Panel Fuse Block..............5-125
Underhood Fuse Block................................5-126
Capacities and Specications........................5-130
Section 5 Service and Appearance Care
5-3

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. If the current load is too heavy,
the circuit breaker opens and then closes after a cool
down period, 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.
5-123

Instrument Panel Fuse Block
The instrument panel fuse
block access door is
located on the driver side
edge of the instrument
panel.
Pull off the cover to access the fuse block.
Fuses Usage
1 Rear Seats
2 Rear Accessory Power Outlet
3 Steering Wheel Controls Backlight
4 Driver Door Module
5Dome Lamps, Driver Side Turn
Signal
6 Driver Side Turn Signal, Stoplamp
7 Instrument Panel Back Lighting
8Passenger Side Turn Signal,
Stoplamp
9Passenger Door Module, Universal
Home Remote System
10 Power Door Lock 2 (Unlock Feature)
11 Power Door Lock 2 (Lock Feature)
12Stoplamps, Center-High Mounted
Stoplamp
13 Rear Climate Controls
14 Power Mirror
15 Body Control Module (BCM)
16 Accessory Power Outlets
17 Interior Lamps
18 Power Door Lock 1 (Unlock Feature)
19 Rear Seat Entertainment
20 Ultrasonic Rear Parking Assist
5-124