
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  

Parking Brake 
To set the  parking  brake, hold the  regular brake pedal 
down with  your  right  foot.  Push down the  parking 
brake pedal  with  your left foot. 
A chime  will activate and the warning light  will  flash 
when the parking brake  is applied and the vehicle 
is  moving  at least 
3 mph (5 km/h)  for  at  least three 
seconds. 
If the  ignition is on  when  the  parking  brake  is released, 
the  brake  system  warning  light  will  go 
off. 
Notice: Driving with  the  parking  brake on can 
cause  your  rear  brakes 
to overheat. You may  have 
to  replace them,  and  you  could  also  damage 
other  parts 
of your  vehicle. 
If you are towing a  trailer  and are parking  on  any  hill, 
see 
Towing a Trailer on page 4-51. 
To release the parking brake, hold the  regular brake 
pedal  down.  Pull the  bottom edge 
of the  lever, located 
above  the parking brake pedal,  with the  parking 
brake  symbol,  to  release the  parking brake. 
2-22  

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  

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  

Battery  Warning  Light Voltmeter  Gage 
If this  light is displayed 
when  the engine  is 
running,  you  may  have a 
problem  with  your  charging 
system. 
The  battery  display  will  also stay on while  the key  is in 
RUN  until  the  engine  is  started. 
If the  light  stays  on  after starting the  engine  it  could 
indicate  a  problem  with  the generator  drive  belt, or  some 
other  charging  system  problem.  Have  it  checked right 
away.  Driving  with  this light displayed could drain 
your  battery. 
If you  must  drive  a  short  distance with this  light 
displayed,  it  helps  to turn 
off all your  accessories,  such 
as  the  radio  and  the  air  conditioner.  When  your 
engine is not  running, but the  ignition  is  in 
RUN,  this gage  shows your battery’s state  of charge  in 
DC volts. 
When  the engine  is running,  the gage shows the 
condition  of the charging  system. Readings between the 
low and high warning  zones indicate the  normal 
operating  range. 
Readings  in the  low  warning  zone  may occur when  a 
large  number 
of electrical accessories are operating  in 
the vehicle and the  engine is left  at an  idle for  an 
extended  period. This condition 
is normal since the 
charging  system is not  able to  provide full  power 
at  engine  idle. 
As engine speeds  are increased, this 
condition should correct  itself as higher  engine speeds 
allow the charging system to create maximum  power. 
3-33  

You can only drive  for  a short time with the  reading  in 
either warning  zone. 
If you  must drive, turn off all 
unnecessary  accessories. 
Readings  in either warning  zone indicate  a possible 
problem  in the  electrical  system.  Have  the vehicle 
serviced as  soon as possible. 
Brake  System  Warning  Light 
With the ignition on,  the brake  system  warning light will 
flash  when  you  set  the parking brake.  The light will 
flash 
if the  parking brake doesn’t release fully.  If  you try 
to drive with the parking brake  engaged,  a  chime 
will  sound  when  the vehicle speed is greater than 
3 mph (5 km/h). 
Your  vehicle’s hydraulic brake  system is divided into  two 
parts. 
If one  part isn’t  working, the other part  can still 
work  and stop  you.  For  good  braking, though,  you  need 
both  parts working  well. 
If the warning light  comes  on  and  a  chime  sounds  there 
could  be  a brake problem.  Have  your brake system 
inspected  right  away. 
I BRAKE I 
- 
United States  Canada 
This light should  come on briefly  when  you  turn  the 
ignition key 
to RUN. If  it doesn’t  come  on  then,  have  it 
fixed 
so it will  be ready to warn  you if there’s  a  problem. 
If the light  comes on while  you  are  driving,  pull off the 
road  and  stop  carefully.  You  may  notice  that  the  pedal  is 
harder 
to push. Or,  the pedal  may  go  closer  to  the 
floor.  It may  take  longer 
to stop.  If  the  light  is  still on, 
have the vehicle  towed  for  service.  See Towing 
Your Vehicle on  page 4-45. 
3-34  

Your brake  system  may  not  be working 
properly 
if the  brake  system warning light is 
on.  Driving  with  the  brake system warning  light 
on  can  lead  to  an  accident. 
If the  light  is still 
on  after  you’ve  pulled 
off the  road  and stopped 
carefully,  have the  vehicle  towed for  service. 
~ 
Anti-Lock  Brake System  Warning 
Light 
With  the anti-lock brake 
system,  this light will come 
on  when  you start  your 
engine  and may  stay on for 
several seconds. That’s 
normal. 
, I 
If the  light doesn’t come on  then, have it fixed so it will 
be ready to  warn you 
if there  is a problem. 
If the light stays  on, or comes on  when  you’re driving, 
your  vehicle needs service. 
You will also  hear  a 
chime sound  when the  light 
is on steady. If the  regular 
brake system warning light isn’t  on, you  still  have 
brakes,  but you  don’t  have anti-lock brakes.  If the 
regular  brake system warning light  is also on you  don’t 
have anti-lock brakes and  there’s  a problem with 
your  regular  brakes. 
In addition to  both lights, you will 
also  hear  a chime sound  on the  first  occurrence  of 
a  problem and each time the car is shut 
off and  then 
restarted.  See 
Brake  System  Warning  Light on 
page 3-34 earlier in this section. 
3-35