2003 GMC SONOMA coolant temperature

6. Start the engine and let it run until you can feel the
upper radiator hose getting hot. Watch out for the
engine cooling fan.
7. By this time, the coolant level inside the radiator
filler neck may be lower. If the level is lower, add
more of the proper DEX-COOL
®coolant mixture
through thefiller neck until the level reaches
the base of thefiller neck.8. Then replace the pressure cap. At any time during
this procedure if coolant begins toflow out of the
filler neck, reinstall the pressure cap. Be sure
the arrow on the pressure cap lines up like this.Engine Fan Noise
This vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the clutch is not engaged. This improves fuel
economy and reduces fan noise. Under heavy vehicle
loading, trailer towing and/or high outside temperatures,
the fan speed increases when the clutch engages.
5-36
2003 - Sonoma OM

What to Use
To determine what kind offluid to use, seePart D:
Recommended Fluids and Lubricants on page 6-33.
Always use the properfluid. Failure to use the proper
fluid can cause leaks and damage hoses and seals.
Windshield Washer Fluid
What to Use
When you need windshield washerfluid, be sure to read
the manufacturer’s instructions before use. If you will be
operating your vehicle in an area where the temperature
may fall below freezing, use afluid that has sufficient
protection against freezing. SeeEngine Compartment
Overview on page 5-10for reservoir location.
Adding Washer Fluid
Open the cap
with the washer
symbol on it.SeeEngine Compartment Overview on page 5-10for
more information on locationt. Add washerfluid until the
tank is full.
Notice:
When using concentrated washeruid, follow
the manufacturer’s instructions for adding
water.
Don’t mix water with ready-to-use washeruid.
Water can cause the solution to freeze and
damage your washeruid tank and other parts
of the washer system. Also, water doesn’t
clean as well as washeruid.
Fill your washeruid tank only three-quarters
full when it’s very cold. This allows for
expansion if freezing occurs, which could
damage the tank if it is completely full.
Don’t use engine coolant (antifreeze) in your
windshield washer. It can damage your
washer system and paint.
5-38
2003 - Sonoma OM

Coolant
Engine Temperature Gage............................3-29
Heater, Engine............................................2-24
Cooling.........................................................3-18
Cooling System..............................................5-30
Crew Cab
®....................................................1-46
Cruise Control.................................................. 3-8
Current and Past Model Order Forms................7-10
Customer Assistance Information
Courtesy Transportation.................................. 7-7
Customer Assistance for Text Telephone (TTY)
Users....................................................... 7-3
Customer Assistance Offices........................... 7-4
Customer Satisfaction Procedure..................... 7-2
GM Mobility Program for Persons with
Disabilities................................................ 7-5
Reporting Safety Defects to General Motors...... 7-9
Reporting Safety Defects to the Canadian
Government.............................................. 7-9
Reporting Safety Defects to the United States
Government.............................................. 7-8
Roadside Assistance Program......................... 7-5
Service Publications Ordering Information......... 7-9
D
Daytime Running Lamps..................................3-12
Defensive Driving............................................. 4-2
Defogging and Defrosting.................................3-19Dinghy Towing................................................4-43
Directing the Airflow ........................................3-17
Doing Your Own Service Work........................... 5-3
Dolly Towing..................................................4-44
Dome Lamp ...................................................3-15
Door
Locks.......................................................... 2-8
Power Door Locks......................................... 2-9
Programmable Automatic Door Locks............... 2-9
Rear Door Security Locks.............................2-11
Third Door..................................................2-12
Driver
Position, Safety Belt.....................................1-16
Driver Information Center (DIC).........................2-46
Driving
At Night.....................................................4-27
City ...........................................................4-31
Defensive..................................................... 4-2
Drunken....................................................... 4-2
Freeway.....................................................4-32
Hill and Mountain Roads..............................4-34
In Rain and on Wet Roads...........................4-28
Winter........................................................4-36
Driving Across an Incline..................................4-22
Driving Downhill..............................................4-21
Driving in Mud, Sand, Snow or Ice....................4-25
Driving in Water..............................................4-26
Driving On Grades
..........................................4-59
Driving on Off-Road Hills
.................................4-18
4
2003 - Sonoma OM

Driving on Snow or Ice....................................4-37
Driving Through Deep Standing Water...............4-30
Driving Through Flowing Water.........................4-30
Driving Uphill..................................................4-19
Driving with a Trailer.......................................4-57
E
Electrical System
Add-On Equipment......................................5-88
Fuses and Circuit Breakers...........................5-89
Headlamps.................................................5-88
Power Windows and Other Power Options......5-88
Windshield Wiper Fuses...............................5-88
Electronic Transfer Case..................................2-30
Emissions Inspection and Maintenance
Programs...................................................3-32
Engine
Air Cleaner/Filter.........................................5-18
Battery.......................................................5-42
Check and Service Engine Soon Light............3-29
Compartment Overview................................5-10
Coolant......................................................5-25
Coolant Heater............................................2-24
Coolant Temperature Gage...........................3-29
Cooling System Inspection............................6-31
Exhaust.....................................................2-37
Fan Noise..................................................5-36Engine (cont.)
Oil .............................................................5-13
Overheating................................................5-28
Starting......................................................2-22
Engine Compartment Fuse Block......................5-91
Engine Coolant Level Check.............................6-26
Engine Oil Additives........................................5-16
Engine Oil Level Check...................................6-26
Entry Lighting.................................................3-14
Environmental Concerns..................................4-15
Exit Lighting...................................................3-14
Express Down Window....................................2-15
Extended Cab (Jump Seat)..............................1-48
Extender, Safety Belt.......................................1-29
Exterior Lamps...............................................3-10
F
Fabric/Carpet.................................................5-79
Filter
Engine Air Cleaner......................................5-18
Finding a PTY Station.....................3-43, 3-50, 3-60
Finding a Station....................3-38, 3-40, 3-48, 3-57
Finish Care....................................................5-83
Finish Damage...............................................5-85
Five-Speed....................................................2-28
Fixed Mast Antenna........................................3-69
Flash-To-Pass Feature....................................... 3-6
5
2003 - Sonoma OM

Flat Tire........................................................5-67
Flat Tire, Changing.........................................5-68
Fluid
Automatic Transmission................................5-20
Manual Transmission....................................5-23
Power Steering...........................................5-37
Windshield Washer......................................5-38
FM ...............................................................3-67
Fog Lamps ....................................................3-13
Following Distance..........................................4-57
Four-Wheel Drive....................................2-29, 5-48
Front Axle......................................................5-49
Front Map Lamps...........................................3-14
Front Storage Area.........................................2-49
Fuel............................................................... 5-4
Additives...................................................... 5-5
California Fuel.............................................. 5-5
Filling a Portable Fuel Container..................... 5-8
Filling Your Tank........................................... 5-6
Fuels in Foreign Countries.............................. 5-6
Gage .........................................................3-35
Gasoline Octane........................................... 5-4
Gasoline Specifications.................................. 5-5
Low Warning Light.......................................3-35
System Inspection
.......................................6-31
Fuses
Fuses and Circuit Breakers
...........................5-89
Windshield Wiper
.........................................5-88G
Gage
Check Gages Warning Light..........................3-34
Engine Coolant Temperature.........................3-29
Fuel..........................................................3-35
Oil Pressure...............................................3-32
Speedometer..............................................3-23
Tachometer.................................................3-23
Voltmeter Gage...........................................3-26
Garment Hooks..............................................2-50
Gasoline
Octane........................................................ 5-4
Specifications............................................... 5-5
Getting Familiar with Off-Road Driving................4-16
Glass Surfaces...............................................5-81
Glove Box.....................................................2-41
GM Mobility Program for Persons with
Disabilities.................................................... 7-5
H
Hazard Warning Flashers................................... 3-3
Head Restraints............................................... 1-7
Headlamp High/Low-Beam Changer.................... 3-6
Headlamps....................................................5-50
Bulb Replacement.......................................5-50
Electrical System.........................................5-88
6
2003 - Sonoma OM

Stalling on an Incline.......................................4-24
Starter Switch Check.......................................6-28
Starting Your Engine.......................................2-22
Shifting Into................................................2-22
Starting Your VORTEC™2200 L4 Engine............ 6-4
Starting Your VORTEC™4300 V6 Engine..........2-23
Steering.......................................................... 4-8
Steering in Emergencies.................................... 4-9
Steering, Suspension and Front Drive
Axle Boot and Seal Inspection.......................6-31
Steering Tips................................................... 4-8
Storage
Garment Hooks...........................................2-50
Storage Areas
Front Storage Area......................................2-49
Glove Box..................................................2-41
Luggage Carrier..........................................2-50
Overhead Console.......................................2-42
Storing a Flat or Spare Tire and Tools...............5-76
Stuck in Sand, Mud, Ice or Snow......................4-40
Sun Visors.....................................................2-16
Sunglasses Storage Compartment.....................2-46
Sunroof.........................................................2-52
Swing-Out Windows........................................2-16
T
Tachometer....................................................3-23
Tailgate.........................................................2-12Tailgate Lubrication Service..............................6-27
Taillamps.......................................................5-55
Temperature and Compass Display....................2-44
Testing the Alarm............................................2-18
Theft-Deterrent, Radio.....................................3-67
Theft-Deterrent Systems...................................2-17
Content Theft-Deterrent
................................2-17
Passlock
®...................................................2-19
Third Door
.....................................................2-12
Throttle System Inspection
...............................6-32
Tilt Wheel
........................................................ 3-4
Time Delay
....................................................2-39
Tire Inflation Check
.........................................6-26
Tires
.....................................................5-58, 5-84
Buying New Tires
........................................5-62
Chains
.......................................................5-66
Changing a Flat Tire
....................................5-68
Compact Spare Tire
.....................................5-78
If a Tire Goes Flat
.......................................5-67
Inflation–Tire Pressure
...............................5-58
Inspection and Rotation
................................5-60
Uniform Tire Quality Grading
.........................5-63
Wheel Alignment and Tire Balance
.................5-64
Wheel Replacement
.....................................5-65
When It Is Time for New Tires
......................5-61
To Use the Engine Coolant Heater
....................2-24
Top of the Instrument Panel
.............................5-81
Top Strap
......................................................1-41
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2003 - Sonoma OM