
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  

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  

The best  way  to  protect the fetus  is to  protect the 
mother. When  a safety belt  is worn  properly, it’s more 
likely that the fetus  won’t be hurt in  a crash. For 
pregnant  women, as for  anyone,  the  key to making 
safety belts  effective is wearing them properly. 
Right  Front  Passenger  Position 
To learn how  to  wear  the right  front passenger’s  safety 
belt  properly,  see 
Driver Position on page 1-13. 
The  right front  passenger’s  safety belt works  the same 
way as the  driver’s safety belt-except  for one thing. 
If you ever pull the shoulder portion  of the  belt out all the 
way,  you will engage the child restraint locking feature 
which  may turn 
off the  passenger’s frontal air  bag.  If this 
happens unintentionally, just  let the  belt  go back all 
the way and  start again. 
Center  Passenger  Position 
1-22  

1. Put  the  restraint  on the seat. 
2. Pick  up  the  latch  plate,  and run the lap and shoulder 
portions 
of the  vehicle’s  safety belt through  or 
around  the  restraint,  The  child restraint instructions 
will  show  you  how. 
4. Pull the  rest of the  shoulder  belt all the way  out of 
the  retractor  to set  the  lock. 
3. Buckle  the  belt.  Make  sure  the  release button  is 
positioned 
so you  would  be  able  to unbuckle the 
safety  belt quickly  if you  ever  had to. 
1-47  

5. Pull the  rest of the shoulder  belt  all the way  out of 
the  retractor  to set the  lock.  6. 
7. 
To tighten the 
belt, feed  the shoulder  belt  back  into 
the  retractor while  you  push  down  on  the  child 
restraint. 
If you’re  using a forward-facing child 
restraint,  you  may find it helpful to  use  your  knee to 
push  down  on  the child restraint as  you tighten  the 
belt.  You  should not  be able to pull  more  of the belt 
out  of the  retractor  once  the  lock has  been  set. 
Push  and  pull the child  restraint in different 
directions to  be sure  it  is secure. 
1-54  

Doors and Locks 
Door Locks 
I 
To lock and unlock  your  vehicle,  do  one  of the  following: 
You can  use  the keyless  entry  system, 
use  your  key, or 
Unlocked  doors  can  be  dangerous. 
e 
e 
e Passengers - especially  children - can 
easily  open  the  doors  and  fall  out  of  a  moving  vehicle.  When  a  door 
is locked,  the 
handle  won’t  open 
it. You  increase  the 
chance  of  being  thrown  out  of  the  vehicle 
in a  crash  if  the  doors  aren’t  locked. So, 
wear  safety  belts  properly  and  lock  the 
doors  whenever  you  drive. 
Young  children  who  get  into  unlocked 
vehicles  may  be  unable  to  get  out. 
A child 
can  be  overcome  by  extreme  heat  and  can 
suffer  permanent  injuries  or  even  death 
from  heat  stroke.  Always  lock  your  vehicle 
whenever  you  leave 
it. 
Outsiders  can  easily  enter  through  an 
unlocked  door  when  you  slow  down  or 
stop  your  vehicle.  Locking  your  doors  can 
help  prevent 
this from  happening. 
e lock  the  door  from  the 
inside  by  sliding the 
manual  lock  lever 
rearward. 
To unlock  the 
door,  slide the  manual 
lock  lever  forward. 
2-6  

Care of Your  (cont.) 
CD  Player 
................................ ... 3-84 
CDS 
.......................................................... 3-84 
Cargo  Lamp 
............................. ... 3-14 
CARGO  LAMP 
ON ....................... ... 3-56 
Cassette  Tape  Messages 
................................. 3-73 
Cassette  Tape  Player  Service 
........................... 6-10 
CD  Adapter  Kits 
............................................. 3-74 
CD  Changer 
................................................... 3-78 
CD  Functions 
................................................. 3-80 
Center  Console  Storage  Area 
........................... 2-39 
Center  High-Mounted  Stoplamp  (CHMSL)  and 
Center  Instrument  Panel  Fuse  Block 
.................. 5-98 
Center  Passenger  Position,  Safety  Belts 
............. 1-22 
Chains,  Tires .................................................. 5-68 
Check  Cargo  Lamp 
............................................... 5-56 
CHANGE  ENGINE  OIL .................................... 3-54 
Engine  Light 
.................................... ... 3-38 
Check  Engine  Light 
.......................... ... 3-38 
CHECK  OIL  LEVEL 
..................................... 3-58 
CHECK  WASHER  FLUID 
................................. 3-58 
Checking  Brake  Fluid 
...................................... 5-40 
Checking  Coolant ............................................ 5-26 
Checking  Engine  Oil 
........................................ 5-14 
Checking  Things Under the Hood 
...................... 5-10 
Checking  Your Restraint  Systems ...................... 1-73 
Chemical  Paint  Spotting 
................................... 5-91  Child  Restraints 
Child  Restraint  Systems 
............................... 1-36 
Infants  and Young  Children 
........................... 1-32 
Lower  Anchorages  and  Top Tethers  for 
Children 
(LATCH System) .......................... 1-43 
Older  Children ............................................. 1-30 
Securing  a Child  Restraint  Designed for the 
Securing  a Child  Restraint  in a Center 
Securing  a  Child  Restraint  in a  Rear 
Securing  a  Child  Restraint in  the Right 
LATCH  System 
........................................ 1-46 
Rear  Seat  Position 
................................... 1-48 
Outside  Seat Position 
............................ 1-46 
Front  Seat Position 
................................... 1-50 
Top Strap ................................................... 1-40 
Top  Strap  Anchor  Location 
............................ 1-41 
Cigarette  Lighter 
............................................. 3-17 
Where 
to Put  the  Restraint 
........................... 1-38 
Cleaning  Inside  of  Your  Vehicle 
.................................. 5-86 
Outside 
of Your  Vehicle ................................ 5-88 
Underbody  Maintenance 
............................... 5-91 
Weatherstrips 
.............................................. 5-88 
Cleaning  Exterior  Lamps/Lenses 
....................... 5-89 
Cleaning  the Mirror 
......................................... 2-30 
Climate  Control  Dual Automatic 
..... . 3-18