2003 GMC SIERRA DENALI heating

Certain electrical accessories may not be compatible
with the accessory power outlets and could result
in blown vehicle or adapter fuses.
If you experience a
problem, see your dealer for additional information
on accessory power outlets.
Notice: Adding some electrical equipment to your
vehicle can damage
it or keep other things from
working
as they should. This wouldn’t be covered by
your warranty. Check with your dealer before
adding electrical equipment, and never use anything
that exceeds the amperage rating.
When adding electrical equipment, be sure to follow the
proper installation instructions included with the
equipment.
Notice: Power outlets are designed for accessory
plugs only. Do not hang any type of accessory
or accessory bracket from the plug. Improper use of
the power outlet can cause damage not covered by your warranty.
Ashtrays and Cigarette Lighter
The ashtray is located in the center console. Press the
raised area on the access door to use the ashtray.
To remove the ashtray first locate the indent on the right
side of the ashtray. Then, place an instrument, such
as a pen, in the indent and pry the ashtray out.
Notice: Don’t put papers or other flammable items
into your ashtrays. Hot cigarettes or other smoking
materials could ignite them, causing a damaging fire.
To use the cigarette lighter, push it in all the way, and
let go. When it’s ready, it will pop back out by itself.
Notice: Don’t hold a cigarette lighter
in with your
hand while
it is heating. If you do, it won’t be able to
back away from the heating element when
it’s
ready. That can make it overheat, damaging the
lighter and the heating element.
3-1 7

Climate Controls
Dual Automatic Climate Control
System
Your vehicle may have the optional dual automatic
climate control system. With this system you can control
the heating, cooling and ventilation for your vehicle.
If your vehicle is equipped with the dual automatic
climate control system, memory seats, and memory
mirrors, you can store and recall the climate control
settings for temperature, air delivery mode, and
fan speed for two different drivers. The personal choice
settings recalled are determined by the transmitter
used to enter the vehicle. After the button with the
unlock symbol on a remote keyless entry transmitter
is pressed, the climate control will adjust to the last
settings of the identified driver. The settings can also be
changed by pressing one of the memory buttons
(1 or 2) located on the driver’s door. When adjustments
are made, the new settings are automatically saved
for that driver.
A 8fj? v (Fan): Press this button to increase or
decrease the fan speed.
0 (Off): Press this button to turn off the entire climate
control system. Outside air will still enter the vehicle, and
will be directed to the floor. This direction can be changed
by pressing the mode button. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is
off.
,% 4d (Mode): Press this button to manually select the air
delivery mode to the floor, panel, or windshield outlets.
This system will stay in the selected mode until the mode
button is pressed again, or the AUTO button, defrost
button, or the off button is pressed. Air delivery mode can
be adjusted while the system is off. A five second status
display will indicate the current mode.
3-1 8

Outlet Adjustment Operation Tips
Use the air outlets located in the center and on the side
of your instrument panel to direct the airflow.
Your vehicle has air outlets that allow you to adjust the
direction and amount of airflow inside the vehicle.
Move the louvers up or down. Use the thumbwheel next
to or underneath the outlet to close the louvers. For
the most efficient airflow and temperature control, keep
the outlet in the fully opened position.
If your vehicle is equipped with rear seat outlets they
can be used
to adjust airflow toward either seating area,
the floor, or upward. Move the center louver up or
down
to direct the airflow. Keep
the hood and front air inlets free
of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
Keep the air path under the front seats clear
of objects. This helps air
to circulate throughout your
vehicle.
Adding outside equipment
to the front of your
vehicle, such as hood-air deflectors, etc., may affect
the performance
of the heating and air conditioning
system. Check with your dealer before adding
equipment
to the outside of your vehicle.
3-23

Engine Coolant Temperature Gage Transmission Temperature Gage
I I
United States
Canada
This gage shows the engine coolant temperature.
It also provides an indicator of how hard your vehicle is
working. During a majority
of the operation, the gage
will read 210°F
(1 00°C) or less. If you are pulling a load
or going up hills, it is normal for the temperature to
fluctuate and approach the 250°F (122°C) mark.
If the
gage reaches the 260°F
(1 25°C) mark, it indicates
that the cooling system is working beyond its capacity.
See
Engine Overheating on page 5-27.
United States Canada
Your vehicle may be equipped with a transmission
temperature gage.
When your ignition is on, the gage shows the
temperature of the transmission fluid. The normal
operating range is from 100°F (38°C)
to about
265°F
(1 30°C).
At approximately 265°F (13O"C), the message center
will display
a TRANSMISSION HOT message and
the transmission will enter
a transmission protection
mode. When the transmission enters the protection
mode, you may notice a change in the transmission
shifting patterns. The transmission will return to normal
shifting patterns when the transmission fluid temperature
falls below 260°F
(1 27°C).
3-36

CHANGE ENGINE OIL
This message is displayed 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 Change
under Engine Oil on page 5-13.
OIL LIFE RESET
This message will appear on the display for about 10
seconds after resetting the change engine oil message.
LOW COOLANT LEVEL
If the engine coolant level is low, this message will
appear on the DIC. Adding coolant will clear the
message.
ENGINE COOLANT HOT
If the cooling system temperature gets hot, this message
will appear in the DIC. Stop the vehicle and let the
engine idle in PARK (P) to allow the coolant to reach a
safe temperature. This message will clear when the
coolant temperature drops to safe operating
temperature.
ENGINE OVERHEATED
If the engine cooling system reaches unsafe
temperatures for operation, this message will appear in
the DIC and you will hear a chime. Stop and turn
off
3-54
the vehicle as soon as it is safe to do so to avoid
severe damage. This message will clear when the
engine has cooled to a safe operating temperature.
OIL PRESSURE LOW
If low oil pressure levels occur, this message will be
displayed on the DIC and a chime will sound. Stop the
vehicle as soon as safely possible and do not operate
it until the cause of the low oil pressure has been
corrected. Check your oil as soon as possible and have
your vehicle serviced.
REDUCED ENGINE POWER
This message is displayed when the cooling system
temperature gets too hot and the engine further enters
the engine coolant protection mode.
See
Engine Overheating on page 5-27 for further
information.
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.

Driving On Grades
Reduce speed and shift to a lower gear before you start
down a long or steep downgrade.
If you don’t shift
down, you might have to use your brakes
so much that
they would get hot and no longer work well.
You can tow in DRIVE
(5). You may want to shift the
transmission to THIRD
(3) or, if necessary, a lower gear
selection
if the transmission shifts too often (e.g.,
under heavy loads and/or hilly conditions).
You may also want to activate the tow/haul mode
if the
transmission shifts too often. See “Tow/Haul Mode”
earlier in this section.
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes.
If you turn your
engine
off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar
to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine
off. If you do get
the overheat warning, see
Engine Overheating on
page
5-27.
Parking on Hills
m
You really should not park your vehicle, with a
trailer attached, on a hill.
If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.
But
if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK
(P) yet.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and shift into PARK (P).
5. Release the regular brakes.
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Section 5 Service and Appearance Care
Service ............................................................ 5.3
Doing Your Own Service Work
......................... 5-4
Adding Equipment to the Outside
of Your Vehicle
........................................... 5-4
Fuel
................................................................ 5.5
Gasoline Octane
............................................ 5.5
Gasoline Specifications
.................................... 5.5
California Fuel
............................................... 5.6
Additives
....................................................... 5.6
Fuels in Foreign Countries
................. ....... 5.7
Filling Your Tank
......................................... 5-7
Filling a Portable Fuel Container
.................... 5-9
the Hood
............................................. 5.10
Hood Release
........................................ ,.5-10
Engine Compartment Overview
....................... 5.12
Checking
Things Under
Engine Oil
................................................... 5.13
Engine Air Cleaner/Filter
................................ 5.19
Engine Coolant
............................................. 5.24
Engine Overheating
....................................... 5.27
Cooling System
............................................ 5.30
Automatic
Transmission Fluid
........................ -5-21
Coolant Surge Tank Pressure Cap
.................. 5-27 Engine
Fan Noise
......................................... 5.36
Power Steering Fluid
..................................... 5.37
Windshield Washer Fluid
................................ 5-38
Brakes
........................................................ 5.39
Battery
........................................................ 5.42
Jump Starting
............................................... 5.43
All-Wheel Drive
......................... .............. 5-49
Rear Axle
....................................................... 5-50
Front Axle
...................................................... 5-51
Bulb Replacement
.......................................... 5-52
Halogen Bulbs
.............................................. 5-52
Headlamps
................................................. -5-52
Roof Marker Lamps
...................................... 5-54
Cargo Lamp
............................................. 5-56
Taillamps
..................................................... 5-58
Replacement Bulbs
....................................... 5-59
Front
Turn Signal, Sidemarker
and Daytime
Running Lamps
......................................... 5-53
Center High-Mounted Stoplamp (CHMSL) and
Pickup
Box Identification and Fender Marker
Lamps
..................................................... 5-58
Windshield Wiper Blade Replacement
.............. 5-60
5-
1

Engine Coolant
The cooling system in your vehicle is filled 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 occurs first, 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, see
Engine Overheating on
page
5-27.
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.
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 occurs first.
Damage caused by the use
of coolant other
than DEX-COOL@ is not covered by your new
vehicle warranty.
Let the warning lights and gages work as they
should.
5-24