
The 1998 GMC Sierra Owner's Manual 
1-1 
2- 1 
3- 1 
4- 1 
5-1 
6-1 
7-1 
8- 1 
9-1 
Seats and Restraint Systems 
This section tells you how to use  your  seats  and safety belts  properly. Tt also explains the air bag  system. 
Features and  Controls 
This section  explains  how to start  and operate  your vehicle. 
Comfort  Controls  and  Audio  Systems 
This section  tells you how  to adjust the ventilation and comfort  controls and how  to operate  your audio  system. 
Your Driving  and  the  Road 
Here you'll  find  helpful  information and tips about  the  road and how to drive  under  different conditions. 
Problems on  the  Road 
This section tells what to  do if you have a problem while driving?  such as a flat tire or overheated  engine,  etc. 
Service and  Appearance  Care 
Here the manual tells you how to keep  your  vehicle running  properly  and looking good. 
Maintenance  Schedule 
This section  tells  you  when to perform  vehicle maintenance and what  fluids  and lubricants to use. 
Customer  Assistance  Information 
This section tells  you  how to contact GMC for  assistance and  how to get  service  and owner  publications. 
It also gives  you information on "Reporting  Safety Defects" on page 8- 10. 
Index 
Here's  an alphabetical  listing  of almost every  subject in this manual.  You can use it to quickly find 
something  you  want to read. 
i 
ProCarManuals.com 

A. Dome  Lamp Switch 
B. Lamp Controls 
C.  Air  Outlets 
D. Multifunction  Lever 
E. Instrument  Cluster 
F. Gearshift Lever 
G.  Audio System 
H. Comfort  Control System 
I. Glove Box 
J. Ashtray 
K. Cupholder 
L. Auxiliary Power Outlets 
M. Storage  Area or Compact Disc Player (If Equipped) 
N. Rear Window Defogger Switch (If  Equipped) 
0. Passenger Air  Bag Off Switch (If Equipped) 
P. Electronic Transfer Case Switch (If Equipped) 
Q. Tilt Lever (If Equipped) 
R. Parking  Brake Release 
S. Hood Release 
T.  Fuse 
Block 
2-61 
ProCarManuals.com 

Section 3 Comfort  Controls  and  Audio  Systems 
In this section,  you’ll find  out how  to operate  the comfort control and  audio  systems offered with your  vehicle.  Be 
sure  to read  about  the particular systems  supplied with your vehicle. 
3-2  3 
-4 
3-5 
3-5 
3-6 
3-6  3 
-7 
3-7 
3-7 
3-8 
3-9 
3-12  Comfort 
Controls 
Air  Conditioning 
Heating 
Ventilation  System 
Defogging and Defrosting  Rear  Window  Defogger 
(If Equipped) 
Audio Systems  Setting  the Clock 
AM-FM  Stereo Radio 
Playing  the Radio 
AM-FM  Stereo with Cassette 
Tape Player 
(If Equipped) 
AM-FM  Stereo with Cassette  Tape and 
Automatic 
Tone Control (If Equipped)  3- 
15 
3- 16 
3-20 
3-2 
1 
3-23 
3-24 
3-25 
3-26 
3-26 
3-26  CD 
Adapter 
Kit 
AM-FM  Stereo with Compact Disc Player and 
Automatic Tone Control 
(If Equipped) 
Remote Compact Disc Player  (If Equipped) 
Theft-Deterrent  Feature 
Understanding Radio Reception 
Tips About  Your Audio System 
Care  of Your  Cassette Tape Player 
Care 
of Your  Compact Discs 
Care  of  Your  Compact Disc Player 
Fixed Mast Antenna 
3-1 
ProCarManuals.com 

. 
NOTICE: 
Don’t  use  a  razor  blade or something  else  sharp 
on  the  inside 
of the  rear  window. If you  do,  you 
could  cut 
or damage  the  warming  grid,  and  the 
repairs  wouldn’t  be  covered 
by your  warranty. 
Audio Systems 
Your  Delco Electronics  audio system  has  been  designed 
to operate easily and give years  of listening pleasure. 
You will  get the  most enjoyment  out of it if you  acquaint 
yourself  with 
it first. Find out what your Delco 
Electronics  system can  do and  how  to  operate 
all its 
controls, 
to be  sure  you’re  getting  the most out of  the 
advanced  engineering  that went  into it. 
Setting  the  Clock for Systems  without 
Automatic  Tone  Control 
Press SET. Within five  seconds,  press and hold the 
SEEK  right arrow 
until the correct  minute appears  on 
the display. Press and 
hold the SEEK left arrow until the 
correct  hour appears 
on the display. 
Setting  the  Clock for Systems  with 
Automatic  Tone 
Control 
Press  and  hold HR until the correct hour  appears on  the 
display. Press  and hold 
MN until the correct minute 
appears  on the display. 
To display the clock with the 
ignition 
off, press RECALL or HR/MN and the time 
will  be displayed  for  a few seconds.  There is  an initial 
two-second  delay before  the clock goes into the 
time-set  mode. 
AM-FM Stereo 
3-7 
ProCarManuals.com 

AM-FM  Stereo  with  Cassette  Tape  and 
Automatic Tone  Control 
(If Equipped) 
Playing the  Radio 
PWR-VOL: Press this knob to  turn  the system on and 
off.  To increase volume,  turn the knob to the right. Turn 
it to the 
left to decrease volume. The knob  is capable of 
being rotated continuously. 
RECALL: Display the time  with the ignition  off  by 
pressing this button.  When the radio  is playing, press 
this button to recall the station frequency. 
SCV Your  system has  a feature  called 
Speed-Compensated-Volume (SCV).  With 
SCV, your 
audio system adjusts automatically to make  up for  road 
and  wind noise as  you drive.  Set the volume at the 
desired level.  Move the control ring behind the upper 
knob to 
the right to adjust the  SCV. Then, as you drive, 
SCV automatically increases the volume, as necessary, 
to overcome noise 
at any  particular speed. The volume 
level should always sound the same 
to you  as you  drive. 
If  you  don’t want to use  SCV,  turn the control all the 
way  down.  Each  notch  on the control ring allows  for 
more volume compensation at  faster vehicle speeds. 
Finding  a Station 
AM-FM: 
Press this button to switch between AM, FMl 
and FM2. The  display  will show your selection. 
TUNE: Press this knob lightly so it extends,  Turn it to 
choose  radio  stations.  Push the knob  back into its stored 
position  when you’re  not using  it. 
SEEK: Press  the  right  arrow  to tune to the  next  higher 
station  and 
the left arrow to  tune  to  the next lower  station 
and stay  there.  The sound  will  mute  while  seeking. 
3-12 
ProCarManuals.com 

AM-FM  Stereo  with  Compact  Disc  Player 
and  Automatic 
Tone Control (If Equipped) 
Playing  the  Radio 
PWR-VOL: 
Press this knob  to turn the system on  and 
off. 
To increase volume, turn this knob to the right. Turn 
it  to 
the left  to decrease  volume. The knob  is capable  of 
rotating continuously. 
RECALL: Display the time  with the ignition  off by 
pressing this button. When the  radio is playing, press 
this button  to recall the station frequency. 
SCV Your  system  has a feature  called 
Speed-Compensated-Volume 
(SCV). With  SCV,  your 
audio  system adjusts automatically to make  up  for road  and  wind 
noise 
as you drive.  Set the volume  at the 
desired level.  Move the control ring behind  the upper 
knob  to 
the right to adjust the SCV. Then, as you drive, 
SCV automatically increases the volume, as necessary, 
to overcome noise  at  any particular speed. The volume 
level should always sound the same 
to you as  you  drive. 
If you  don’t  want  to  use  SCV,  turn the control all the 
way  down.  Each notch on the control ring allows  for 
more  volume compensation at faster vehicle speeds. 
Finding  a  Station 
AM-FM: Press this button to  switch between  AM,  FM1 
and 
FM2. The  display  will show your selection. 
TUNE: Press this knob lightly so it extends. Turn it to 
choose radio stations.  Push the knob back into its stored 
position when  you’re 
not using it. 
SEEK: Press  the  right  arrow  to  tune  to the  next  higher 
station  and  the  left  mow to  tune 
to the  next  lower  station 
and  stay  there.  The  sound  will  mute  while  seeking. 
SCAN: Press and hold  SEEK for two seconds  until 
SCAN  appears  on  the display. 
SCAN allows  you to 
listen to stations for a few seconds. The receiver  will 
continue  to  scan and momentarily  stop at each station 
until you press the button again. The sound will mute 
while  scanning. 
ProCarManuals.com 

Tips About  Your Audio System 
Hearing damage from loud noise is almost undetectable 
until 
it is too late.  Your  hearing can adapt to higher 
volumes  of sound. Sound  that seems normal can  be  loud 
and harmful 
to your hearing. Take precautions  by 
adjusting  the volume control on your radio to  a  safe 
sound level before your hearing adapts  to 
it. 
To help avoid hearing loss or damage: 
Adjust the volume control to the lowest setting. 
0 Increase volume slowly until you hear  comfortably 
and clearly. 
NOTICE: F 
Before  you add  any  sound  equipment to your 
vehicle -- like a  tape  player,  CB  radio,  mobile 
telephone  or  two-way  radio 
-- be sure  you can 
add  what  you want. 
If you  can,  it’s very 
important  to  do  it  properly.  Added  sound  equipment  may  interfere  with  the  operation 
of 
your  vehicle’s  engine, Delco Electronics  radio or 
other  systems,  and  even damage  them.  Your 
vehicle’s  systems  may  interfere  with the 
operation  of sound  equipment  that  has  been 
added  improperly. 
So, before  adding  sound  equipment,  check  with 
your  dealer  and  be sure  to  check  Federal  rules 
covering  mobile  radio  and  telephone  units. 
ProCarManuals.com 

Battery 
Every new vehicle  has an ACDelco  Freedom@ battery. 
You  never have to add water to  one of these.  When it’s 
time  for a new battery,  we recommend  an ACDelco 
Freedom  battery. Get  one that has the replacement 
number  shown 
on the  original  battery’s  label. 
Vehicle  Storage 
If you’re not going  to  drive  your vehicle  for 25 days 
or  more, remove the  black, negative 
(-) cable from 
the battery.  This 
will help keep your battery from 
running  down. 
Batteries  have  acid  that  can  burn  you and  gas 
that  can  explode.  You can  be  badly  hurt  if 
you 
aren’t  careful.  See  “Jump  Starting”  in  the  Index 
for  tips  on working  around 
a battery  without 
getting  hurt.  Contact 
your dealer  to  learn how 
to prepare your vehicle 
for longer  storage  periods. 
Also, for your  audio system.  see “Theft-Deterrent 
Feature” 
in the Index. 
Bulb Replacement 
Before you replace  any bulbs,  be sure that  all the lamps 
are  off and the  engine isn‘t running.  See “Replacement 
Bulbs” 
in the Index for the proper types of bulbs to use. 
1 6!!, CAUTION: 
Halogen  bulbs  have  pressurized  gas  inside  and 
can  burst  if you  drop  or  scratch  the  bulb. 
You or 
others  could  be  injured.  Be sure  to  read 
and 
follow  the  instructions  on  the  bulb  package. 
6-39 
ProCarManuals.com