2003 GMC SONOMA radio

Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. Your vehicle
was designed and tested with top-quality GM brake parts.
When you replace parts of your braking system—for
example, when your brake linings wear down and you
need new ones put in—be sure you get new approved
GM replacement parts. If you don’t, your brakes may no
longer work properly. For example, if someone puts in
brake linings that are wrong for your vehicle, the balance
between your front and rear brakes can change—for the
worse. The braking performance you’ve come to expect
can change in many other ways if someone puts in the
wrong replacement brake parts.
Battery
Your new vehicle comes with a maintenance free
ACDelco®battery. When it’s time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an ACDelco
®
battery. SeeEngine Compartment Overview on
page 5-10for battery location.
Warning:Battery posts, terminals and related
accessories contain lead and lead compounds,
chemicals known to the State of California to cause
cancer and reproductive harm. Wash hands after
handling.
Vehicle Storage
If you’re not going to drive your vehicle for 25 days or
more, remove the black, negative (−) cable from
the battery. This will help keep your battery from
running down.
{CAUTION:
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren’t careful. See“Jump Starting”next for
tips on working around a battery without
getting hurt.
Contact your dealer to learn how to prepare your
vehicle for longer storage periods.
Also, for your audio system, seeTheft-Deterrent
Feature (Non-RDS Radios) on page 3-67or
Theft-Deterrent Feature (RDS Radios) on page 3-67.
5-42
2003 - Sonoma OM

Jump Starting
If your battery 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 don’t 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 wouldn’t be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won’t 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 system isn’t a 12-volt system
with a negative ground, both vehicles can be
damaged.
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 brakefirmly 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 (N).
Notice:If you leave your radio on, it could be badly
damaged. The repairs wouldn’t be covered by
your warranty.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or in the accessory power outlets. Turn off
the radio and all lamps that aren’t needed. This will
avoid sparks and help save both batteries. And it
could save your radio!
5-43
2003 - Sonoma OM

Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from
short circuits by a combination of fuses and circuit
breakers. This greatly reduces the chance offires
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.
Instrument Panel Fuse Block
The instrument panel fuse
block is located at the end
of the instrument panel
on the driver’s side of
the vehicle.
Remove the cover by turning the fastener
counterclockwise. Extra fuses and the fuse extractor
are provided in the cover. To reinstall the fuse
panel cover, push in and turn the fastener clockwise.
5-89
2003 - Sonoma OM

Fuse Usage
A Not Used
B Not Used
1 Not Used
2 Cigarette Lighter, Data Link
Connector
3 Cruise Control Module and Switch,
Body Control Module, Heated SeatsFuse Usage
4 Gages, Body Control Module,
Instrument Panel Cluster
5 Parking Lamps, Power Window
Switch, Body Control Module,
Ashtray Lamp
6 Steering Wheel Radio Controls
7 Headlamps Switch, Body Control
Module, Headlamp Relay
8 Courtesy Lamps, Battery Run-Down
Protection
9 Heating, Ventilation, Air Cooling
Control Head (Manual)
10 Turn Signal
11 Cluster, Engine Control Module
12 Interior Lights
13 Auxiliary Power
14 Power Locks Motor
15 4WD Switch, Engine Controls
(VCM, PCM, Transmission)
16 Supplemental Inflatable Restraint
17 Front Wiper
18 Steering Wheel Radio Controls
19 Radio, Battery
5-90
2003 - Sonoma OM

Fuse Usage
20 Amplifier
21 Heating, Ventilation, Air Cooling
(Manual), Heating,Ventilation,
Air Cooling (Automatic), Heating,
Ventilation, Air Cooling Sensors
(Automatic)
22 Anti-Lock Brakes
23 Rear Wiper
24 Radio, IgnitionEngine Compartment Fuse Block
The engine compartment fuse block is located under
the hood on the driver’s side of the vehicle. SeeEngine
Compartment Overview on page 5-10for more
information on location.
Remove the cover by turning the fastener
counterclockwise. To reinstall the fuse panel cover,
push in and turn the fastener clockwise.
5-91
2003 - Sonoma OM

A
Accessory Power Outlets.................................3-15
Adding Equipment to Your Air Bag-Equipped
Vehicle.......................................................1-63
Adding Washer Fluid.......................................5-38
Additional Program Information........................... 7-8
Additives, Fuel................................................. 5-5
Add-On Electrical Equipment............................5-88
Add-On Equipment..........................................4-48
Adjusting the Speakers
(Balance/Fade)....................3-39, 3-42, 3-49, 3-59
After Off-Road Driving.....................................4-26
Air Bag
Off Light.....................................................3-24
Readiness Light..........................................3-24
Air Bag System..............................................1-54
Adding Equipment to Your Air Bag-Equipped
Vehicle...................................................1-63
Air Bag Off Switch.......................................1-60
How Does an Air Bag Restrain?....................1-58
Servicing Your Air Bag-Equipped Vehicle.........1-63
What Makes an Air Bag Inflate?....................1-58
What Will You See After an Air Bag
Inflates?..................................................1-58
When Should an Air Bag Inflate?...................1-57
Where Are the Air Bags?..............................1-56
Air Cleaner/Filter, Engine.................................5-18
All Overseas Locations...................................... 7-4Aluminum Wheels...........................................5-84
AM ...............................................................3-67
AM-FM Radio.................................................3-37
Antenna, Fixed Mast.......................................3-69
Anti-Lock Brake System.................................... 4-6
Anti-Lock Brake, System Warning Light..............3-28
Appearance Care............................................5-79
Care of Safety Belts....................................5-82
Chemical Paint Spotting...............................5-85
Cleaning the Inside of Your Vehicle................5-79
Cleaning the Outside of Your Vehicle..............5-82
Finish Damage............................................5-85
GM Vehicle Care/Appearance Materials..........5-86
Sheet Metal Damage...................................5-85
Underbody Maintenance
...............................5-85
Weatherstrips
..............................................5-82
Approaching a Hill
..........................................4-18
Ashtrays
........................................................3-16
Assist Handles
...............................................2-50
Audio System(s)
.............................................3-36
AM-FM Radio
.............................................3-37
Care of Your Cassette Tape Player
................3-68
Care of Your CD Player
...............................3-69
Care of Your CDs
........................................3-69
Fixed Mast Antenna
.....................................3-69
Radio with Cassette and CD
.........................3-47
Radio with CD
............................................3-40
Radio with Six-Disc CD
................................3-56
1
2003 - Sonoma OM

Audio System(s) (cont.)
Setting the Time for Radios with Radio
Data Systems (RDS)................................3-37
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-36
Theft-Deterrent Feature................................3-67
Understanding Radio Reception.....................3-67
Automatic Headlamp System............................3-11
Automatic Transmission...................................2-22
Fluid..........................................................5-20
Operation...................................................2-25
Automatic Transmission Check..........................6-27
Automatic Transmission Shift Lock Control
System Check.............................................6-29
B
Backing Up....................................................4-58
Battery..........................................................5-42
Battery Replacement......................................... 2-6
Battery Rundown Protection.............................3-15
Bed Rails......................................................2-52
Before Leaving on a Long Trip.........................4-33
Before You Go Off-Roading..............................4-13
Body Lubrication Service..................................6-28
Brake
Parking......................................................2-32
System Inspection.......................................6-32Brake (cont.)
System Warning Light..................................3-27
Brake Adjustment............................................5-41
Brake Fluid....................................................5-39
Brake Pedal Travel.........................................5-41
Brake Wear...................................................5-41
Brakes..........................................................5-39
Braking........................................................... 4-5
Braking in Emergencies..................................... 4-7
Break-In, New Vehicle.....................................2-20
Bulb Replacement...........................................5-50
Center High-Mounted Stoplamp (CHMSL)........5-54
Halogen Bulbs............................................5-50
Headlamps.................................................5-50
One-Piece Front Turn Signal Lamps...............5-52
Replacement Bulbs......................................5-55
Taillamps....................................................5-55
Two-Piece Front Turn Signal Lamps...............5-53
Buying New Tires...........................................5-62
C
California Fuel.................................................. 5-5
Canada........................................................... 7-4
Canadian Owners................................................ ii
Canadian Roadside Assistance........................... 7-6
Capacities and Specifications............................5-94
Carbon Monoxide...................4-36, 4-51, 2-12, 2-37
2
2003 - Sonoma OM

Parking
Brake........................................................2-32
Over Things That Burn.................................2-36
Parking Brake and Automatic Transmission
Park (P) Mechanism Check...........................6-30
Parking on Hills..............................................4-59
Parking Your Vehicle.......................................2-36
Part A - Scheduled Maintenance Services............ 6-4
Part B - Owner Checks and Services................6-26
Part C - Periodic Maintenance Inspections..........6-31
PartD-Recommended Fluids and Lubricants....6-33
PartE-Maintenance Record...........................6-35
Passing.................................................4-10, 4-58
Passlock
®......................................................2-19
Payload.........................................................4-48
Pickup Conversion to Chassis Cab....................4-50
Plan Ahead When Possible................................ 7-7
Playing a Cassette Tape..................................3-52
Playing a Compact Disc..................3-45, 3-54, 3-62
Playing a Specific Loaded
Compact Disc
.............................................3-63
Playing the Radio
...................3-37, 3-40, 3-47, 3-56
Power
Accessory Outlets
........................................3-15
Door Locks
.................................................. 2-9
Electrical System
.........................................5-88
Lumbar Controls
........................................... 1-5
Seat
............................................................ 1-4Power (cont.)
Steering Fluid.............................................5-37
Windows....................................................2-15
Power Steering................................................ 4-8
Programmable Automatic Door Locks.................. 2-9
Q
Questions and Answers About Safety Belts.........1-15
R
Radiator Pressure Cap....................................5-27
Radio Messages.............................3-39, 3-45, 3-52
Radios..........................................................3-36
AM-FM Radio.............................................3-37
Care of Your Cassette Tape Player................3-68
Care of Your CD Player...............................3-69
Care of Your CDs ........................................3-69
Radio with Cassette and CD.........................3-47
Radio with CD............................................3-40
Radio with Six-Disc CD................................3-56
Setting the Time for Radios with Radio
Data Systems (RDS)................................3-37
Setting the Time for Radios without Radio
Data Systems (RDS)................................3-36
Theft-Deterrent............................................3-67
Understanding Reception..............................3-67
RDS Messages..............................3-43, 3-51, 3-61
11
2003 - Sonoma OM