service indicator CHEVROLET ASTRO 1996 Owners Manual
Page 118 of 372
Malfunction  Indicator Lamp 
(Service  Engine  Soon  Light) 
SERVICE 
ENGINE 
SOON 
Your vehicle  is  equipped 
with  a computer  which 
monitors  operation  of  the 
fuel,  ignition  and  emission 
control  systems. 
This  system 
is called  OBD I1 (On-Board 
Diagnostics-Second  Generation)  and  is  intended  to 
assure  that emissions are  at acceptable  levels  for  the 
life  of  the  vehicle,  helping  to produce a  cleaner 
environment.  (In  Canada, 
OBD I1 is  replaced  by 
Enhanced  Diagnostics.)  The SERVICE  ENGINE SOON 
light comes on  to  indicate  that  there is a problem  and 
service  is  required.  Malfunctions  often will  be  indicated 
by  the  system  before  any  problem  is apparent,  which 
may  prevent  more  serious  damage to your  vehicle.  This 
system  is  also  designed  to assist  your service  technician 
in  correctly  diagnosing  any  malfunction. 
NOTICE: 
If  you  keep  driving  your  vehicle  with  this  light 
on,  after  a  while,  your  emission  controls  may  not 
work  as well,  your  fuel  economy  may  not  be  as 
good  and  your  engine  may  not  run  as smoothly. 
This  could  lead  to costly  repairs  that  may  not  be 
covered  by  your  warranty. 
This  light  should  come on, as a check to  show you it is 
working,  when  the  ignition  is 
on and  the  engine is not 
running.  If the  light  doesn’t  come on,  have  it repaired. 
This  light  will  also come 
on during a malfunction  in  one 
of  two  ways: 
Light  Flashing -- A misfire  condition  has  been 
detected. 
A misfire  increases  vehicle  emissions  and 
may  damage  the emission control  system 
on your 
vehicle.  Dealer  or qualified  service  center  diagnosis 
and  service  is  required. 
0 Light  On  Steady -- An emission  control  system 
malfunction  has  been  detected  on  your  vehicle. 
Dealer  or qualified  service center  diagnosis  and 
service  may  be  required. 
2-58  
Page 233 of 372
Fuel 
Use regular  unleaded ‘gasoline rated at 87 octane  or 
higher.  At a minimum,  it should  meet specifications 
\. 
ASTM D4814 in the  United States and CGSB  3.5-M93 
in  Canada. Improved  gasoline specifications have been 
developed  by the  American  Automobile  Manufacturers 
Association  (AAMA) for better vehicle  performance 
and  engine  protection.  Gasolines meeting the AAMA 
specification could provide  improved driveability  and 
emission  control  system  protection  compared-to 
other gasolines. 
Be  sure  the  posted  octane  is at  least 
87. If the  octane  is 
less than 
87, you  may  get a heavy  knocking noise  when 
you  drive.  If it’s  bad  enough,  it can  damage your engine. 
If you’re  using  fuel  rated  at 87 octane  or  hgher and  you 
still hear  heavy  knocking,  your  engine  needs  service.  But 
don’t  worry 
if you  hear  a little  pinging  noise  when  you’re 
accelerating  or  driving 
up a  hill.  That’s  nomal, and  you  don’t 
have  to  buy  a higher  octane  fuel  to  get  rid  of pinging.  It’s  the 
heavy,  constant  knock  that  means  you  have  a problem.  If 
your vehicle  is certified’  to  meet California  Emission 
Standards  (indicated on the underhood tune-up  label), 
it  is designed  to operate  on fuels  that  meet  California 
I 
specifications.  If such fuels are  not available  in states 
adopting  California  emissions  standards, your vehicle 
will  operate  satisfactorily on fuels meeting federal 
specifications,  but emission  control  system performance 
may  be  affected.  The malfunction indicator  lamp on 
your  instrument  panel may turn on and/or  your vehicle 
may  fail a smog-check  test. If this  occurs, return  to  your 
authorized  GM dealer  for diagnosis  to determine the 
cause  of failure.  In the event  it is determined that  the 
cause  of the  condition  is the type of fuels used, repairs 
may  not  be  covered by your  warranty. 
.In  Canada,  some gasolines  contain an octane-enhancing 
additive called  MMT.  If  you use such fuels,  your 
emission  control system performance  may deteriorate 
and  the malfunction indicator lamp on  your instrument 
panel  may turn on. 
If this happens, return to  your 
authorized  GM dealer  for  service. 
6-3  
Page 264 of 372
Using the  wrong  fluid  can  badly  damage 
brake  system  parts.  For  example,  just 
a few 
drops  of mineral-based  oil, such  as  engine 
oil,  in  your  brake  system  can  damage  brake 
system  parts 
so badly that they’ll  have  to  be 
replaced.  Don’t let  someone  put  in  the 
wrong  kind  of fluid. 
If  you  spill  brake  fluid  on  your  vehicle’s 
painted  surfaces,  the  paint  finish  can  be 
damaged.  Be careful  not  to  spill  brake  fluid 
on  your  vehicle. 
If you do,  wash  it off 
immediately.  See  “Appearance  Care”  in 
the  Index. 
I A CAUTION: 
The  brake  wear  warning  sound  means  that 
sooner  or  later  your  brakes  won’t work well. 
That  could  lead  to  an  accident.  When  you hear 
the  brake  wear  warning  sound,  have  your  vehicle  serviced. 
NOTICE: 
Continuing  to  drive with  worn-out  brake  pads 
could  result 
in costly  brake  repair. 
Brake Wear 
Your vehicle has front  disc  brakes  and  rear  drum  brakes. 
Disc  brake  pads  have  built-in  wear  indicators  that  make 
a high-pitched  warning  sound  when  the  brake  pads  are 
worn  and  new  pads  are  needed. 
The sound  may  come  and 
go  or  be  heard  all  the  time  your  vehicle 
is moving  (except 
when  you  are  pushing 
on the  brake  pedal  firmly).  Some  driving  conditions  or  climates  may  cause  a  brake 
squeal  when  the  brakes  are  first  applied  or  lightly  applied. 
This  does  not  mean  something 
is wrong with your  brakes. 
Free  movement 
of brake  calipers  and  properly  torqued 
wheel  nuts  are  necessary  to  help  prevent  brake 
pulsation.  When  tires  are  rotated,  inspect  brake  calipers 
for movement,  brake  pads  for  wear,  and  evenly  torque 
wheel  nuts 
in the  proper  sequence to GM specifications. 
6-34  
Page 275 of 372
When It’s Time for New Tires 
One way to tell  when  it’s 
time  for new  tires  is to 
check  the  treadwear 
indicators, which  will 
appear  when your tires have 
only 
1/16 inch (1.6 mm)  or 
less  of tread remaining. 
You  need  a new  tire if any  of the  following  statements 
are  true: 
0 You  can see the indicators at three  or more  places 
around the  tire. 
You can  see  cord  or fabric showing through  the 
0 The  tread  or  sidewall is cracked,  cut  or  snagged deep 
tire’s 
rubber. 
enough 
to show cord or fabric. 
0 The  tire  has  a bump, bulge  or split. 
The  tire has  a puncture,  cut or other  damage.  that, 
can’t  be repaired  well because  of the  size  or  location 
of  the damage. 
.. 
Buying New Tires 
To  find  out what  kind  and size of tires  you  need, look at 
the  Certificatiooire  label. 
The  tires installed  on your vehicle  when it was  new  had 
a  Tire  Performance Criteria  Specification (TPC Spec) 
number  on each  tire’s  sidewall.  When  you  get new  tires, 
get ones  with that same  TPC Spec  number.  That way 
your  vehicle will  continue to have tires that are designed 
to  give  proper  endurance,  handling, speed rating, 
traction, ride and  other  things  during  normal service on 
your vehicle.  If your tires have  an all-season tread 
design, the TPC number  will  be followed  by 
an “MS” 
(for mud and snow). 
If  you  ever replace your tires  with those  not having 
a 
TPC  Spec  number,  make sure they  are the  same size, 
load  range,  speed  rating and construction  type (bias, 
bias-belted  or  radial) as your original tires.  
Page 365 of 372
Instrumentpanel ............................... 2-50 
Brightness  Control 
.................... i ....... 2-35 
Cleaning 
.................................... 6-53 
Cluster 
..................................... 2-52 
FuseBlock 
.................................. 6-61 
Interior  Lamps 
................................. 2-37  Charging  System 
........................... 2-55 
Check Gages 
................................ 2-63 
Check  Oil 
................................... 2-61 
Daytime  Running  Lamps Indicator 
............... 2-62 
Safety  Belt Reminder 
..................... 1 - 12.  2-54 
Service Engine  Soon 
.......................... 2-58 
Loading  Your  Vehicle 
........................... 4-26 . 
J 
Locks 
ack.  Tire .................................... 5-24 
Cylinders ................................... 7-42 
Jump  Starting ................................... 5-2 
Door ........................................ 2-5 
Key  Lock Cylinders Service 
..................... 7-42 
Keyless  Entry  System 
............................ 2-7 
Keys 
.......................................... 2-1 
Key  Lock  Cylinder Service ..................... 7-42 
PowerDoor 
.................................. 2-6 
Sliding  Door  Child  Security 
..................... 2-10 
Steering  Column Lock  Check 
................... 7-44 
Lubricants  and  Fluids 
............................ 7-47 
Lubrication  Service.  Body 
........................ 7-42 
Luggagecarrier 
................................ 2-47 
Certificationflire 
............................. 4-26  Lumbar Controls ................................ 1-2 
Service Parts  Identification ..................... 6-59 
Tire-Loading  Information 
...................... 4-26 
Vehicle  Identification  Number 
................... 6-59 
Lamps ........................................ 2-35 
Dome 
...................................... 2-37 
Interior 
..................................... 2-37 
OnReminder 
................................ 2-36 
Latches.  Seatback ................................ 1-5 
Leaving  Your  Vehicle ............................. 2-6 
Leaving  Your  Vehicle  with  the  Engine Running 
....... 2-24 
Lighter 
....................................... 2-48 
Lights 
Air Bag  Readiness ....................... 1-25.  2-54 
Anti-Lock  Brake System  Warning 
............ 2-57. 4-6 
Brake  System  Warning 
......................... 2-57  Maintenance. 
Normal  Replacement  Parts 
........... 6-69 
Maintenance  Record 
............................ 7-49 
Maintenance  Schedule 
............................ 7-1 
Long  Trip/Highway  Definition 
................... 7-5 
Long TripMighway  Intervals 
..................... 7-5 
Owner Checks  and Services 
..................... 7-41 
Periodic  Maintenance  Inspections 
................ 7-45 
Recommended Fluids  and  Lubricants 
............. 7-47 
Scheduled  Maintenance  Services 
.................. 7-2 
Short  Trip/City  Definition 
....................... 7-4 
Short Trip/City  Intervals ........................ 7-4 
Maintenance.  Underbody ......................... 6-X 
9-5  
Page 366 of 372
Maintenance  When  Trailer  Towing ............... 4-36 
Malfunction  Indicator  Lamp 
...................... 2-58 
ManualFrontSeat 
............................... 1-1 
Manual  Lumbar  Support .......................... 1-2 
Methanol 
...................................... 6-4 
Mirrors 
....................................... 2-38 
Convex  Outside 
.............................. 2-39 
Inside  Day/Night  Rearview 
..................... 2-38 
Outside 
..................................... 2-39 
Visor  Vanity ................................. 2-49 
MMT 
......................................... 6-3 
ModelReference 
................................. vi 
Mountain  Roads ........ ................ 4-20 
Net.  Convenience 
.............................. 2-46 
Neutral 
....................................... 2-19 
New  Vehicle  Break-In 
........................... 2-  I3 
Nightvision 
................................... 4-13 
Odometer 
.................................... 2-53 
Odometer.  Trip 
................................. 2-53 
Off-Road  Recovery 
............................. 4- IO 
Oil.  Engine .................................... 6-11 
Opener.  Garage  Door ............................ 2-43 
Outside  Mirror 
................................. 2-39 
Overhead  Console 
.............................. 2-42 
Overheating  Engine 
............................. 5- I3 
Owner  Checks  and  Services 
....................... 7-41 
Owner  Publications.  Ordering ...................... 8-9 
Paint  Spotting.  Chemical ........................ 6-57 
Park 
......................................... 2-18 
Shifting  Into 
................................. 2-22 
Shifting  Out 
of ............................... 2-25 
AtNight 
.................................... 2-13 
Brake ...................................... 2-21 
Brake  Mechanism  Check 
....................... 7-44 
Lots 
....................................... 2-13 
Over  Things  That  Burn 
......................... 2-25 
With 
a Trailer ................................ 4-36 
Passing 
....................................... 4-10 
Payload 
....................................... 4-28 
Periodic  Maintenance  Inspections 
.................. 7-45 
Power  Accessory  Outlet 
............................. 2-49 
DoorLocks 
................................... 2-5 
Option  Fuses 
................................ 6-60 
Seat ......................................... 1-3 
Steering ..................................... 4-8 
Steering  Fluid 
................................ 6-30 
Windows 
.................................... 2-27 
Pregnancy,  Use  of Safety  Belts 
.................... 1-30 
Problems  on  the  Road 
............................ 5-1 
Publications,  Service  and  Owner .................... 8-9 
Parking 
Radiator 
..................................... 5-19 
Radiator  Pressure  Cap ........................... 6-29 
Radio  Reception 
................................ 3-26 
Radios 
........................................ 3-8 
Rain.  Driving In ................................ 4-14 
Reading 
Lamps ................................ 2-38 
9-6