
The 2003 GMC  Sierra Denali Owner  Manual a 
Seats  and  Restraint  Systems ........................... 1-1 
Front  Seats ............................................... 1-2 
Rear  Seats 
............................................... 1-7 
Safety  Belts 
.............................................. 1-8 
Child  Restraints 
....................................... 1-30 
Air  Bag  Systems 
...................................... 1-57 
Restraint  System  Check 
............................ 1-73 
Features  and  Controls 
..................................... 2-1 
Keys 
........................................................ 2-2 
Doors  and  Locks 
....................................... 2-6 
Windows 
................................................. 2-1 0 
Theft-Deterrent  Systems ............................ 2-1 3 
Starting  and Operating Your Vehicle ........... 2-15 
Mirrors 
.................................................... 2-28 
Onstar@  System 
...................................... 2-33 
HomeLink@  Transmitter 
............................. 2-35 
Storage  Areas 
......................................... 2-39 
Instrument  Panel 
............................................. 3-1 
Vehicle 
Personalization 
............................. 2-42 
Instrument  Panel  Overview 
.......................... 3-2 
Climate  Controls 
...................................... 3-1 8 
Warning  Lights,  Gages  and  Indicators 
......... 3-24 
Driver Information Center  (DIC) 
.................. 3-43 
Audio  System(s) 
....................................... 3-61  Driving  Your  Vehicle 
....................................... 4-1 
Your 
Driving, the  Road, and Your  Vehicle ..... 4-2 
Towing 
................................................... 4-45 
Service  and Appearance Care 
.......................... 5-1 
Service 
..................................................... 5-3 
Fuel 
......................................................... 5-5 
Checking  Things  Under  the  Hood 
............................................. 5-10 
All-Wheel  Drive 
........................................ 5-49 
Rear  Axle 
............................................... 5-50 
Front Axle 
............................................... 5-51 
Bulb  Replacement 
.................................... 5-52 
Windshield  Wiper Blade Replacement 
......... 5-60 
Tires 
...................................................... 5-61 
Appearance  Care 
..................................... 5-86 
Vehicle  Identification 
................................. 5-94 
Electrical  System 
...................................... 5-95 
Capacities  and Specifications 
................... 5-1 04 
Normal  Maintenance  Replacement  Parts 
.... 5-1 05 
Maintenance  Schedule 
..................................... 6-1 
Maintenance  Schedule 
................................ 6-2 
Customer Assistance  Information 
.................... 7-1 
Customer  Assistance  Information 
.................. 7-2 
Reporting Safety  Defects 
............................ 7-9 
Index 
................................................................. 1  

These are  some examples of vehicle  symbols you may find on your vehicle: 
POSSIBLE /r 
CAUTION 
INJURY 
PROTECT  EYES  BY 
SHIELDING 
CAUSTIC 
ACID  COULD  BATTERY 
CAUSE 
BURNS 
AVOID 
SPARKS 
OR 
FLAMES 
SPARK 
OR 
COULD  FLAME 
'\Ir8 
EXPLODE 
BAlTERY  LATCH  BOTH  LAP  AND 
SHOULDER  BELTS  TO 
PROTECT  OCCUPANT 
48: @ 
DO  NOT  TWIST  SAFm 
BELT  WHEN  AlTACHING 
FASTEN  SEAT 
BELTS 
MOVE  SEAT  FULLY 
\v! 
REARWARD* /g 
SECURE 
CHILD  SEAT 
PULL  BELT 
COMPLETELY 
THEN  SECURE  CHILD 
SEAT 
DO NOT  INSTALL 
A  REAR-FACING 
CHILD  RESTRAINT 
@o 
POSITION 8 
IN  THIS  SEATING 
DO  NOT  INSTALL 
A 
CHILD  RESTRAINT p? 
FORWARD-FACING  IN  THIS  SEATING  POSITION 
8 
DOOR  LOCK 
UNLOCK  SGHTING 
- MASTER SWITCH B- / ,  
SIGNALS @e 
TURN 
PARKING 
PC 
LAMPS 
RUNNING 
*:{io 
DAYTIME  LAMPS 
LAMPS 
#O 
ENGINE 
COOLANT 
cc. 
TEMP 
CHARGING  BAlTERY 
SYSTEM 
COOLANT 
ENGINE  OIL  PRESSURE 
W& 
ANTI-LOCK (@) 
BRAKES 
FE E] 
ACCESS 
COOLANT 
m-1 
ENGINE  FAN 
OWNERS  MANUAL 
SERVICE 
MANUAL 
V  

Section Seats  and  Restraint  Systems 
Front  Seats ..................................................... .l -2 
Power  Seats ............................. .............. 1-2 
Power  Lumbar ............................................... 1-3 
Heated  Seats 
................................................. 1-3 
Reclining  Seatbacks 
........................................ 1-4 
Head  Restraints 
............................................. 1-6 
Rear  Seats 
....................................................... 1 -7 
Rear  Seat  Operation 
....................................... 1-7 
Safety  Belts 
..................................................... 1-8 
Questions  and  Answers  About  Safety  Belts 
...... 1-1 2 
How  to Wear  Safety  Belts  Properly 
................. 1-13 
Driver Position 
.............................................. 1.1 3 
Safety  Belt  Use  During Pregnancy 
.................. 1-21 
Right  Front  Passenger  Position 
....................... 1-22 
Safety  Belts:  They 
Are for  Everyone 
................. 1-8 
Center  Passenger  Position 
............. ..... 1-22 
Rear  Seat  Passengers 
...................... ..... 1-24 
Rear  Safety  Belt  Comfort  Guides  for  Children  and  Small  Adults 
.......................... 1-27 
Safety  Belt  Extender 
......................... ..... 1-29 
Child  Restraints 
............................. ..... 1-30 
Older  Children 
.............................................. 1-30 
Infants  and  Young  Children ............................ 1-32 
Child  Restraint  Systems 
................................ -1-36 
Where  to Put  the  Restraint 
............................. 1-38 
Top  Strap 
................................................... .l -40 
Top  Strap  Anchor Location ............................. 1.41 
Children  (LATCH  System) 
....................... 1-43 
for  the  LATCH  System 
............................... 1-46 
Outside  Seat Position 
................................ 1-46 
Rear  Seat  Position 
.................................... 1-48 
Front  Seat Position 
.................................... 1-50 
Air  Bag  Systems ....................... .............. 1-57 
Where  Are  the Air  Bags? 
............................ 1-59 
When  Should  an  Air  Bag  Inflate? .................... 1-61 
What  Makes  an Air  Bag  Inflate? 
..................... 1-61 
Lower  Anchorages  and  Top 
Tethers for 
Securing  a Child  Restraint  Designed 
Securing  a Child  Restraint  in a  Rear 
Securing  a Child  Restraint  in a  Center 
Securing  a Child  Restraint 
in the  Right 
How  Does  an Air  Bag  Restrain? 
..................... 1-62 
What  Will You  See  After  an  Air  Bag  Inflates? 
... 1-62 
Air  Bag 
Off Switch ........................................ 1-64 
Passenger  Sensing  System 
............................ 1-68 
Servicing  Your  Air  Bag-Equipped  Vehicle 
......... 1-72 
Adding  Equipment  to Your  Air  Bag-Equipped 
Vehicle 
.................................................... 1-72 
Restraint System  Check 
.................................. 1-73 
Checking  Your  Restraint Systems ................... 1-73 
Replacing  Restraint  System Parts 
After  a  Crash 
.............................. ...... .l -73 
1-1  

Q: 
A: 
If I’m  a  good  driver, and I never drive far from 
home,  why  should 
I wear safety  belts? 
You  may  be  an  excellent driver, but 
if you’re in an 
accident 
- even  one  that isn’t your fault - you  and 
your  passengers  can  be hurt. Being  a  good 
driver  doesn’t  protect  you  from things beyond your 
control,  such as bad  drivers. 
Most  accidents  occur  within 
25 miles (40 km)  of 
home.  And  the  greatest number of serious injuries 
and  deaths  occur  at  speeds  of  less than 
40 mph 
(65 km/h). 
Safety  belts are  for everyone. 
How to Wear  Safety  Belts  Properly 
This part is  only  for people of adult size. 
Be  aware  that  there are special things to  know about 
safety  belts and children.  And there are different 
rules  for  smaller  children and babies.  If  a child will  be 
riding  in your  vehicle,  see 
Older Children  on page 1-30 
or lnfants  and  Young  Children on page 1-32. Follow 
those  rules for  everyone’s  protection. 
First, you’ll  want  to  know  which  restraint systems  your 
vehicle  has. 
Driver Position 
This  part describes  the driver’s restraint system. 
Lap-Shoulder Belt 
The  driver  has  a lap-shoulder belt. Here’s  how to wear  it 
properly. 
1. Close  and lock the door. 
2. Adjust  the seat so you  can  sit  up  straight. To see 
how,  see  “Seats’’  in the  Index. 
We’ll  start  with  the  driver  position. 
1-13  

Rear  Safety  Belt  Comfort Guides for 
Children  and  Small  Adults 
Your vehicle  may have this feature already.  If it doesn't, 
you can get  it  from  any 
GM dealer. 
Rear  seat  comfort guides provide added safety  belt 
comfort for  older children  who  have outgrown booster 
seats and  for small  adults.  When  installed on a shoulder 
belt,  the comfort  guide better positions the  belt away 
from the  neck and  head. 
To unlatch the belt,  just  push the  button on the  buckle. 
1-27  

Accident statistics show  that  children  are  safer if they 
are  restrained in the  rear  seat. 
In  a  crash,  children who are  not  buckled  up can  strike 
other  people  who are buckled  up,  or  can  be  thrown 
out  of the  vehicle.  Older  children  need to  use  safety 
belts properly. 
Child Restraints 
Older Children 
Q: 
A: 
Older children  who have outgrown booster seats should 
wear  the vehicle’s  safety  belts.  What 
is the proper 
way to wear safety belts? 
If possible,  an older  child should  wear  a 
lap-shoulder belt  and  get the additional  restraint  a 
shoulder  belt can provide.  The  shoulder  belt 
should  not  cross the  face  or  neck.  The  lap  belt 
should 
fit snugly  below  the hips,  just touching  the 
top  of the  thighs. 
It should  never  be worn  over 
the  abdomen,  which  could cause  severe  or  even 
fatal internal injuries in 
a crash. 
If you have the  choice,  a  child should sit  in a seat that 
has  a lap-shoulder belt to  get the additional restraint 
a  shoulder belt  can provide. 
1-30  

- 
!ver do this. 
Here  two  children  are  wearing  the  same  belt. 
The  belt  can’t  properly  spread  the  impact 
forces. 
In a  crash,  the  two  children  can  be 
crushed  together  and  seriously  injured. 
A belt 
must  be used  by  only  one  person  at  a  time. 
Q: What  if  a  child is wearing  a  lap-shoulder  belt, 
but  the  child  is 
so small  that  the  shoulder  belt 
is  very  close  to  the  child’s  face  or  neck? 
be  sure  that the  shoulder  belt stili  is  on  the  child’s 
shoulder, 
so that  in a crash  the child’s  upper 
body  would  have the  restraint  the belts provide. 
If the child  is sitting  in a rear  seat  outside position, 
see 
Rear  Safety Belt Comfort Guides  for Children 
and  Small  Adults 
on page 1-27. 
If the child  is so small that  the  shoulder  belt  is  still 
very  close  to the child’s  face  or  neck,  you  might 
want  to place  the child  in a seat  that  has  a  lap belt, 
if your vehicle  has  one. 
A: Move  the  child toward  the center  of the  vehicle,  but 
1-31  

1 
Never do this. 
Here  a  child is sitting in a  seat  that  has  a 
lap-shoulder  belt,  but  the  shoulder  part  is 
behind  the  child. 
If the  child  wears  the  belt in 
CAUTION:  (Continued)  way, 
in a  cra-.. 
2 c .... d mig---  slide  under 
the  belt. The  belt’s  force  would  then  be  applied 
right  on  the  child’s  abdomen.  That could  cause 
serious 
or fatal  injuries. 
Wherever  the child sits,  the lap portion 
of the  belt 
should  be  worn  low and  snug  on  the hips,  just touching 
the child’s thighs. This applies belt force to  the  child’s 
pelvic  bones  in a  crash. 
Infants and Young Children 
Everyone  in a vehicle  needs protection!  This  includes 
infants  and  all  other children.  Neither  the  distance 
traveled  nor the age  and  size  of the  traveler  changes 
the  need,  for  everyone, 
to use safety  restraints.  In fact, 
the  law  in every state  in the  United  States  and  in 
every  Canadian  province says children  up 
to some  age 
must  be  restrained while 
in a  vehicle. 
Every time infants 
and young  children  ride in vehicles, 
theyshould  have the  protection provided  by  appropriate 
restraints.  Young children should  not  use  the  vehicle’s 
adult safety belts  alone, unless there is  no  other  choice. 
Instead, they  need to use  a child  restraint. 
1-32