
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  

Vehicle Damage  Warnings 
Also, in this  book  you  will find these notices: 
Notice: These mean there is something  that could 
damage 
your vehicle. 
A notice will tell  you about  something  that can  damage 
your  vehicle.  Many times,  this damage  would  not be 
covered  by your  warranty,  and it could  be  costly. But the 
notice  will tell  you  what  to do  to  help avoid the 
damage. 
When  you read other manuals,  you might  see  CAUTION 
and  NOTICE  warnings in different colors  or 
in different 
words. 
You’ll  also see warning labels  on your vehicle.  They  use 
the  same  words,  CAUTION  or NOTICE. 
Vehicle Symbols 
Your  vehicle  has  components  and  labels that  use 
symbols  instead 
of text. Symbols,  used on  your  vehicle, 
are  shown  along with  the  text describing  the operation 
or  information relating to  a  specific  component, control, 
message,  gage  or  indicator. 
If you  need  help figuring  out  a  specific  name of a 
component,  gage  or  indicator  reference  the  following 
topics  in the  Index: 
Seats  and  Restraint Systems in Section 1 
Features  and Controls  in Section 2 
Instrument Panel  Overview in Section 3 
Climate Controls in  Section 3 
Warning Lights, Gages  and  Indicators in  Section 3 
Audio System(s)  in  Section 3 
Engine  Compartment  Overview  in Section 5 
iv  

Mirrors 
Automatic  Dimming  Rearview  Mirror 
with  Onstar@,  Compass and 
Temperature  Display 
Your vehicle  may have this  feature.  When  on,  an 
electrochromic  mirror  automatically  dims  to the  proper 
level to  minimize  glare  from  lights behind you after  dark. 
The  mirror  also  includes  a duel  display  in  the  upper 
right corner  of the  mirror  face.  The  compass reading and 
the outside  temperature  will  both appear in the  display 
at  the  same  time. 
cl) (On/Off): This  is  the  on/off  button. 
Temperature and  Compass  Display 
Press  the  on/off  button,  located  to  the  far  left,  briefly  to 
turn  the  comp/temp  display  on  or  off. 
If the  display  reads CAL, you  will need to calibrate  the 
compass.  For  more information  on  calibration,  see  below. 
To  adjust  between  Fahrenheit  and  Celsius  do  the 
following: 
1. Press  and hold  the  on/off  button  for  approximately 
four  seconds until  either  a  flashing 
OF, or "C 
appears. 
desired  unit of  measurement.  After  approximately 
four  seconds  of  inactivity,  the  new  unit  will  be  locked 
in  and  the  compass/temperature  display  will  return. 
2. Press  the  button again  to  change  the  display  to  the 
Electrochromic  Mirror  Operation 
The electrochromic  (self  dimming)  mirror  function is 
turned  on  automatically  each  time  the  ignition  is  started. 
To  operate  the electrochromic  mirror  do  the following: 
1. Make  sure  the  green  indicator  light,  located  to  the  left 
of  the  on/off  button,  is  lit. 
If it's  not,  press  and  hold  the 
on/off  button  for  approximately  six  seconds  until  the 
green  light comes  on, indicating  that  the  mirror  is  in 
electrochromic  (self  dimming)  mode. 
2. Turn  off the  electrochromic  mirror  function  by 
pressing  and holding  the  on/off  button  for 
approximately  six  seconds  until  the  green  indicator 
light  turns  off. 
2-28  

Section 3 Instrument  Panel 
I~s~Pu~~~IP Panel OWWV~~W ............................... 3.2 
Hazard  Warning  Flashers 
................................ 3.3 
Other  Warning  Devices ................................... 3.4 
Horn 
............................................................. 3.4 
Tilt  Wheel 
..................................................... 3.4 
Turn  SignaVMultifunction  Lever 
......................... 3.5 
Exterior  Lamps 
............................................. 3.11 
Interior  Lamps 
.............................................. 3.15 
Accessory  Power  Outlets 
............................... 3.16 
Ashtrays  and  Cigarette  Lighter 
........................ 3.17 
Climate  Controls 
............................................ 3.18 
Dual  Automatic  Climate  Control System 
........... 3.18 
Warning  Lights,  Gages  and Indicators 
............. 3.24 
Instrument  Panel  Cluster 
................................ 3.25 
Speedometer  and  Odometer 
........................... 3.26 
Tachometer 
................................................ -3-26 
Safety  Belt  Reminder  Light 
............................. 3.26 
Air  Bag  Readiness  Light 
................................ 3-27 
Passenger  Air  Bag  Status  Indicator 
................. 3.30 
Battery  Warning  Light 
.................................... 3.33 
Brake  System  Warning  Light 
.......................... 3.34 
Anti-Lock  Brake  System  Warning  Light 
............. 3.35 
Air 
Bag 
Off Light .......................................... 3-28 
Voltmeter  Gage 
............................................ 3-33 
Engine  Coolant  Temperature  Gage 
..... ..... 3.36  Transmission Temperature 
Gage 
..................... 3.36 
Malfunction Indicator  Lamp 
............................. 3.38 
Oil  Pressure  Gage 
........................................ 3-40 
Cruise  Control  Light 
...................................... 3.41 
Tow/Haul  Mode  Light 
.................................... 3-41 
Fuel  Gage 
................................................... 3.42 
Driver  Information  Center  (DIC) 
....................... 3.43 
DIC  Operation and  Displays 
........................... 3.43 
DIC  Warnings  and  Messages 
......................... 3.53 
Audio  System(s) 
............................................. 3.61 
Setting  the Time 
...................... .......... 3.6 1 
Radio  with  Cassette  and  CD ..... .............. 3.62 
Rear  Seat  Audio  (RSA) 
............................. 3.76 
CD  Changer 
................................................ 3-78 
Theft-Deterrent  Feature 
................................. -3-81 
Audio  Steering  Wheel Controls 
....................... 3.81 
Understanding  Radio  Reception 
...................... 3-82 
Care  of Your  Cassette  Tape  Player 
................ -3-83 
Care  of  Your  CDs 
......................................... 3.84 
Care  of  Your  CD  Player 
................................ 3.84 
Fixed  Mast  Antenna 
...................................... 3.84 
XMTM Satellite  Radio  Antenna  System 
............. 3.84 
DAB  Radio  Antenna  System 
........................... 3.84 
Low  Fuel  Warning  Light 
................................. 3-42  

Exterior Lamps 
The control  on the driver’s  side  of the instrument panel 
operates  the exterior  lamps. 
Turn  the control  clockwise  to operate the  lamps. 
The  exterior  lamp  control  has four  positions: 
0 (OFF): Turning  the control  to this  position turns off 
the  Daytime  Running  Lamps  (DRL),  and the automatic 
headlamps.  An  indicator  light will illuminate when 
this  position  is selected.  AUTO 
(Automatic):  Turning the control to this  position 
puts the system into  automatic headlamp  mode. 
An 
indicator light will  illuminate  when this position  is 
selected. 
:oO: (Parking Lamps): Turning  the control to this 
position turns  on the  parking lamps, together with  the 
following: 
Sidemarker Lamps 
Taillamps 
License Plate Lamps 
0 Instrument Panel Lights 
Roof  Marker Lamps  (If  Equipped) 
$0 (Headlamps):  Turning the control to this  position 
turns on the headlamps,  together with the previously 
listed lamps and  lights. 
You  can switch  your headlamps  from high to  low-beam 
by  pushing the turn signal/multifunction lever towards 
the  instrument  panel. 
3-1 1  

Automatic Headlamp System 
When it  is dark  enough  outside, your automatic 
headlamp  system  will turn on your  headlamps  at the 
normal  brightness along with other  lamps  such as 
the taillamps, sidemarker, parking  lamps  and the 
instrument panel lights. The  radio lights will also  be  dim. 
Your  vehicle is  equipped with a  headlamp  off  delay, 
which  will keep  the  headlamps  on  for  a short  time  after 
the  ignition is turned 
off. For  more  information  see 
DIC Operation and  Displays  on page 3-43. 
Your vehicle  has a light  sensor  located  on the top  of the 
instrument panel in the  defroster grille.  Be sure it is 
not  covered,  or the  system  will be  on  whenever 
the  ignition  is on. 
The  system  may  also turn on your  headlamps  when 
driving through a  parking garage,  heavy overcast 
weather  or  a tunnel. This  is normal. 
There  is  a  delay in the transition  between the daytime 
and nighttime operation  of the  Daytime  Running 
Lamps  (DRL)  and  the automatic headlamp  systems 
so 
that  driving under bridges  or bright  overhead  street 
lights  does  not  affect  the  system. The  DRL  and 
automatic  headlamp  system  will only be affected  when 
the  light  sensor  sees  a change  in lighting lasting 
longer than  the  delay.  one 
minute  for the  automatic  headlamp  system  to 
change  to DRL 
if it is bright  enough  outside.  During that 
delay, your instrument panel cluster  may  not  be as 
bright as  usual.  Make  sure  your  instrument panel 
brightness control  is in  the  full bright  position.  See 
“Instrument Panel Brightness  Control’’  under 
Interior 
Lamps  on  page 
3-15. 
To idle your vehicle  with  the automatic  headlamp 
system  off,  turn the control  to the 
off position. 
You  may  be  able  to turn  off  your  automatic  headlamp 
system.  See  Daytime  Running  Lamps  (DRL)  later  in this 
section  for  more  information. 
Your  headlamps  will also stay  on after you  exit  the 
vehicle.  You can program  this  feature using  the  Driver 
lnforrnation Center.  See 
Driver  lnforrnation  Center  @IC) 
on  page 
3-43 
As  with  any  vehicle, you should turn  on  the  regular 
headlamps 
if you  need  them. 
Lamps On  Reminder 
A reminder  chime will sound  when  your  headlamps  or 
parking  lamps are manually  turned on  and  your 
ignition is  off, in LOCK,  ACCESSORY,  or  your  door  is 
open.  To disable the  chime, turn the light 
off, then 
back  on. 
If  you  start your vehicle  in a dark garage, the automatic 
headlamp  system  will  come  on  immediately. Once 
you  leave  the garage, it will take  approximately 
3-1 2  

Front Reading Lamps Interior Lamps 
Instrument  Panel Brightness Control 
-g-: This feature  controls  the brightness of the 
instrument  panel lights. 
The  thumbwheel  for  this  feature is located next 
to the 
exterior  lamp  control. 
Turn  the  thumbwheel  up to adjust  the instrument panel 
lights  and  return  the  radio display to full  brightness 
when  the  headlamps  or  parking lamps are on.  To  turn 
on  the  dome  lamps,  with  the vehicle doors closed, 
turn  the  thumbwheel  all  the way  up. 
Exit  Lighting 
With  exit  lighting,  the  interior lamps will come  on  when 
you  remove  the  key  from  the ignition.  The  lamps 
will  not  come  on 
if the  dome  override button  is pressed 
in. 
Entry  Lighting 
Your  vehicle  is equipped  with an illuminated entry 
feature. 
When  a door  is opened,  the dome  lamps  and  puddle 
lamps  will  come  on 
if the  dome  override button is in the 
out  position.  If the  dome  override button  is pressed 
in,  the  lamps  will not  come  on.  Your 
vehicle  has front  reading  lamps located  in the 
overhead  console. Press  the round  button  located next 
to the lamp to turn the  lamp  on.  The  lamps  can  be 
adjusted to  point  in the direction  you  want  them  to go. 
Press  the button again  to turn  the  lamp 
off. 
3-1 5  

Warning Lights, Gages and 
Indicators 
This  part describes the warning lights and  gages that 
may  be  on your vehicle.  The pictures will help  you 
locate  them. 
Warning  lights and  gages  can signal that  something is 
wrong  before  it becomes  serious enough 
to cause 
an  expensive  repair or  replacement. Paying attention to 
your warning lights and  gages could also  save  you 
or others from injury. 
Warning  lights come  on  when  there may  be  or is a 
problem  with one of your vehicle’s functions. 
As you  will 
see  in  the  details  on  the next few pages,  some 
warning  lights come  on  briefly when  you  start the 
engine just  to let  you  know  they’re working.  If  you are 
familiar with  this section,  you  should not be  alarmed 
when  this happens.  Gages  can 
indicate when there may  be  or  is  a  problem 
with  one of your  vehicle’s  functions.  Often  gages 
and  warning lights  work  together 
to let  you  know  when 
there’s  a  problem  with your  vehicle. 
When  one  of  the warning lights  comes  on  and  stays  on 
when  you  are driving,  or  when  one  of  the  gages 
shows  there may  be  a  problem,  check  the  section  that 
tells  you  what  to do  about 
it. Please  follow  this 
manual’s  advice.  Waiting to do repairs  can  be 
costly 
- and  even  dangerous. So please  get to know 
your  warning lights  and  gages.  They’re  a  big help. 
Your  vehicle also  has a driver information  system that 
works  along with  the warning  lights and  gages.  See 
Driver  lnformation  Center (DIC) on  page 3-43. 
3-24