2003 GMC SIERRA heating

Engine Coolant
The cooling system in your vehicle isfilled with
DEX-COOL®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occursfirst, if you add only
DEX-COOL
®extended life coolant.
The following explains your cooling system and how to
add coolant when it is low. If you have a problem
with engine overheating, seeEngine Overheating on
page 5-26.
A 50/50 mixture of clean, drinkable water and
DEX-COOL
®coolant will:
•Give freezing protection down to−34°F(−37°C).
•Give boiling protection up to 265°F (129°C).
•Protect against rust and corrosion.
•Help keep the proper engine temperature.
•Let the warning lights and gages work as they
should.
Notice:When adding coolant, it is important that
you use only DEX-COOL
®(silicate-free) coolant.
If coolant other than DEX-COOL®is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the engine
coolant will require change sooner -- at 30,000 miles
(50,000 km) or 24 months, whichever occursfirst.
Damage caused by the use of coolant other
than DEX-COOL
®is not covered by your new vehicle
warranty.
5-23
2003 - Sierra Denali

Coolant Surge Tank Pressure Cap
The coolant surge tank
pressure cap must be fully
installed on the coolant
surge tank.
Notice:Your pressure cap is a pressure-type cap
and must be tightly installed to prevent coolant loss
and possible engine damage from overheating.
See“Capacities and Specifications”for more
information.
Engine Overheating
You willfind a coolant temperature gage on your
vehicle’s instrument panel. SeeEngine Coolant
Temperature Gage on page 3-36. In addition, you will
find a LOW COOLANT, ENGINE OVERHEATED and a
REDUCED ENGINE POWER message in the DIC on
the instrument panel. SeeDriver Information Center
(DIC) on page 3-42.
Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternatesfiring
groups of cylinders helps prevent engine damage. In
this mode, you will notice a loss in power and engine
performance. This operating mode allows your vehicle to
be driven to a safe place in an emergency. Driving
extended miles (km) and/or towing a trailer in the
overheat protection mode should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. See“Engine Oil”in the Index.
5-26
2003 - Sierra Denali

Windshield Wiper Blade
Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. SeeAt Least Twice
a Year on page 6-10for more information.
Replacement blades come in different types and are
removed in different ways. For proper type and length,
seeNormal Maintenance Replacement Parts on
page 5-100.To replace the windshield wiper blade assembly do the
following:
1. Lift the wiper arm and turn the blade until it is
facing away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver’s side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.
Tires
Your new vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to obtain service,
see your GMC Warranty booklet for details.
{CAUTION:
Poorly maintained and improperly used tires
are dangerous.
•Overloading your tires can cause
overheating as a result of too much
friction. You could have an air-out and a
serious accident. See“Loading Your
Vehicle”in the Index.
CAUTION: (Continued)
5-56
2003 - Sierra Denali

Driving (cont.)
Drunken....................................................... 4-2
Freeway.....................................................4-36
Hill and Mountain Roads..............................4-38
In Rain and on Wet Roads...........................4-32
Winter........................................................4-40
Driving Across an Incline..................................4-27
Driving Downhill..............................................4-25
Driving in Mud, Sand, Snow or Ice....................4-28
Driving in Water..............................................4-29
Driving On Grades..........................................4-59
Driving on Off-Road Hills.................................4-23
Driving on Snow or Ice....................................4-40
Driving Through Deep Standing Water...............4-34
Driving Through Flowing Water.........................4-34
Driving Uphill..................................................4-24
Driving with a Trailer.......................................4-58
Dual Automatic Climate Control System.............3-18
E
Easy Exit Seat...............................................2-42
Electrical System
Add-On Equipment......................................5-91
Fuses and Circuit Breakers...........................5-91
Power Windows and Other Power Options......5-91
Windshield Wiper Fuses...............................5-91
Electrochromic Mirror Operation........................2-28
Emissions Inspection and Maintenance
Programs...................................................3-39Engine
Air Cleaner/Filter
.........................................5-18
Battery
.......................................................5-39
Check and Service Engine Soon Light
............3-37
Compartment Overview
................................5-12
Coolant
......................................................5-23
Coolant Heater
............................................2-18
Coolant Temperature Gage
...........................3-36
Cooling System Inspection
............................6-14
Exhaust
.....................................................2-26
Fan Noise
..................................................5-34
Oil
.............................................................5-13
Overheating
................................................5-26
Starting
......................................................2-17
ENGINE COOLANT HOT
.................................3-52
Engine Coolant Level Check
.............................6-10
Engine Hour Meter Display
...............................3-26
Engine Oil Additives
........................................5-16
Engine Oil Level Check
...................................6-10
ENGINE OVERHEATED
..................................3-52
Entry Lighting
.................................................3-15
Environmental Concerns
..................................4-20
Erasing HomeLink
®Buttons
..............................2-38
Exit Lighting
...................................................3-15
Express-Down Windows
...................................2-12
Extender, Safety Belt
.......................................1-28
Exterior Lamps
...............................................3-11
5
2003 - Sierra Denali

H
Hazard Warning Flashers................................... 3-4
Head Restraints............................................... 1-5
Headlamp High/Low Beam Changer.................... 3-6
Headlamps....................................................5-48
Bulb Replacement.......................................5-48
Front Turn Signal, Sidemarker and Daytime
Running Lamps........................................5-49
Halogen Bulbs............................................5-48
Pickup Box Identification and Fender
Marker Lamps.........................................5-54
Roof Marker Lamps.....................................5-51
Heated Seats................................................... 1-3
Heating.........................................................3-22
Highway Hypnosis...........................................4-38
Hill and Mountain Roads..................................4-38
Hitches..........................................................4-57
HomeLink
®Transmitter, Programming................2-35
HomeLink®Transmitter....................................2-35
Hood
Checking Things Under................................5-10
Release.....................................................5-10
Horn ............................................................... 3-5
How to Add Coolant to the Coolant Surge Tank......5-30
How to Add Fluid............................................5-22
How to Check........................................5-20, 5-57
How to Check Lubricant...................................5-46
How to Check Power Steering Fluid..................5-35How to Inspect...............................................5-18
How to Use This Manual...................................... ii
How to Wear Safety Belts Properly...................1-12
Hydroplaning..................................................4-33
I
If No Steam Is Coming From Your Engine..........5-28
If Steam Is Coming From Your Engine...............5-27
If the Light is Flashing.....................................3-38
If the Light Is On Steady.................................3-38
If You Are Stuck in Sand, Mud, Ice or Snow.......4-44
If You Do Decide To Pull A Trailer.....................4-53
If You’re Caught in a Blizzard...........................4-42
Ignition Positions.............................................2-16
Ignition Transmission Lock Check......................6-13
Illuminated Visor Vanity Mirrors.........................2-13
Infants and Young Children, Restraints...............1-31
Inflation -- Tire Pressure..................................5-57
Inspection
Brake System
.............................................6-15
Engine Cooling System
................................6-14
Exhaust System
..........................................6-14
Fuel System
...............................................6-14
Part C - Periodic Maintenance
.......................6-14
Steering and Suspension
..............................6-14
Transfer Case and Front Axle
(All-Wheel Drive)
......................................6-15
7
2003 - Sierra Denali