check engine GMC ENVOY 1998 Repair Manual
Page 352 of 386
Starter Switch Check  Brake-Transmission  Shift  Interlock (BTSI) Check 
When  you  are doing this check,  the  vehicle  could 
move  suddenly. 
If it does,  you  or  others could  be 
injured.  Follow  the steps below. 
A CAUTION: 
I 
When  you  are  doing this check,  the  vehicle  could 
move  suddenly.  If  it  does,  you 
or others  could  be 
injured.  Follow  the  steps below. 
1. Before you start, be sure you have  enough  room 
around 
the vehicle. 
2. Firmly apply both the  parking brake  (see  “Parking 
Brake” 
in the Index if necessary)  and the 
regular  brake. 
NOTE: 
Do not  use the  accelerator  pedal, and be 
ready 
to turn  off the engine  immediately if it starts. 
3. Try to start the  engine in each gear.  The  starter 
should work only  in  PARK (P) or  NEUTRAL  (N). 
If  the  starter  works in any  other  position,  your 
vehicle  needs service. 
1. Before  you start,  be sure  you have  enough  room 
around  the vehicle. 
It should be parked  on a 
level  surface. 
2. Firmly apply  the parking brake (see “Parking  Brake” 
in  the Index  if necessary). 
NOTE:  Be ready to apply the regular brake 
immediately  if the  vehicle begins  to  move. 
3. With the engine  off, turn the key to the RUN 
position,  but don’t start the  engine. Without  applying 
the  regular  brake, try 
to move the shift lever  out of 
PARK 
(P) with normal effort.  If the shift lever 
moves out  of  PARK 
(P), your vehicle’s BTSI 
needs  service. 
7-41 
! 
ProCarManuals.com 
Page 353 of 386
Ignition Transmission Lock Check 
While parked, and  with the parking brake set, try to turn 
the ignition  key to LOCK 
in each shift lever position. 
The  key should turn to LOCK only when the shift 
lever is in  PARK (P). 
The key should  come out only in LOCK. 
Parking  Brake  and  Automatic Transmission 
PARK 
(P) Mechanism Check 
b- 
When  you are doing  this check,  your vehicle 
could  begin  to move. 
You or  others  could be 
injured  and  property  could be damaged. Make 
sure  there  is room in  front 
of your vehicle  in case 
it begins to roll.  Be  ready to apply  the  regular 
brake 
at once  should  the vehicle  begin  to move. 
Park  on a fairly steep hill, with the vehicle facing 
downhill.  Keeping  your foot 
on the regular brake, set  the 
parking brake. 
0 To  check  the parking  brake’s holding ability: 
With  the  engine running and transmission  in 
NEUTRAL 
(N), slowly  remove  foot pressure  from 
the regular brake pedal. 
Do this until  the vehicle  is 
held  by the  parking brake only. 
0 To check  the PARK (P) mechanism’s holding ability: 
With  the  engine running,  shift to  PARK 
(P). Then 
release  all brakes. 
Underbody Flushing Service 
At least every spring, use plain water to flush any 
corrosive materials from the underbody.  Take care 
to 
clean thoroughly any  areas where  mud and other debris 
can collect. 
7-42 
ProCarManuals.com 
Page 371 of 386
1998 GMC SERVICE PUBLICATIONS  ORDERING INFORMATION 
The following publications covering the operation and servicing of your vehicle can  be purchased  by filling 
the  Service Publication  Order  Form  in  this  book  and mailing  it in  with  your  check,  money  order, 
or credit card information to  Helm, Incorporated (address below.) 
CURRENT  PUBLICATIONS FOR 1998 GMC 
SERVICE  MANUALS 
Service Manuals  have  the diagnosis and repair  information 
on engines, transmission,  axle, suspension, brakes, 
electrical, steering,  body, etc. 
RETAIL  SELL  PRICE:  $90.00 
TRANSMISSION,  TRANSAXLE, TRANSFER  CASE 
UNIT  REPAIR  MANUAL 
This manual  provides information  on unit  repair  service 
procedures, adjustments  and specifications  for the 
1998  GM transmissions, transaxles  and transfer cases. 
RETAIL  SELL PRICE: 
$40.00 
SERVICE  BULLETINS 
Service Bulletins give technical service information  needed 
to  knowledgeably service General  Motors cars  and trucks. 
Each  bulletin contains instructions to assist in the 
diagnosis  and service  of your  vehicle. 
PLEASE  COMPLETE  THE ORDER  FORM SHOWN  ON 
THE FOLLOWING  PAGE  AND  MAIL TO: 
Helm,  Incorporated P.O. Box 07130 Detroit,  MI  48: 
OWNER’S  INFORMATION 
Owner publications are written directly  for Owners  and 
intended to provide basic operational information  about 
vehicle.  The owner’s  manual will include the  Maintenanl 
Schedule  for all models. 
In-Portfolio: Includes a Portfolio,  Owner’s  Manual  and 
Warranty Booklet.  RETAIL  SELL  PRICE:  $15.00 
Without  Portfolio:  Owner’s  Manual only. 
RETAIL  SELL PRICE: 
$1 0.00 
CURRENT & PAST  MODEL  ORDER  FORMS 
Service Publications are available  for current  and past 
model 
GM vehicles. To request  an order  form, please 
specify  year and  model  name 
of the vehicle. 
OR  ORDER  TOLL  FREE: 1-800-782-4356 
Monday-Friday  8:OO AM - 6:OO PM  Eastern  Tme 
For  Credit  Card  Orders  Only 
(VISA-MasterCard-Discovr 
ProCarManuals.com 
Page 374 of 386
Section 9 Index 
Accessory Inf’lator ............................. 2-50 
Acces~~ty 
POWC~ Outlets ......................... 2-52 
Adcling  Sound Equilm1cnt 
........................ 3-23 
Add-On  Equiptnent 
............................. 4-43 
Air Bag 
Adding  Equipment ............................ 1-27 
How Does it Restrain .......................... 1-25 
How it Works ................................ I -23 
Location 
.................................... 1-23 
Readiness  Light 
......................... 1-22 . 2-63 
Servicing 
................................... 1-27 
What 
Makes it Inflate .......................... 1-25 
What 
You See After it Inflates ................... 1-25 
When  Should 
it Inflate ......................... 1-24 
Air Cleaner .................................... 6- 14 
Air Conditioning ................................ 3-5 
Refripxants 
................................. 6-62 
Alignment 
and Balancc.  Tire ...................... 6-13 
Atltenn.1. 
Fi~d ................................. 3-26 
Adcling 
Equipment 
to the Outside of’ Your Vehicle ...... 6-3 
AllIt11inLll11 Wheels . Clea11i11~ ...................... 6-5 1 
Anti-Lock Brake System  Wa~ming  Light ......... 2-66 . 4-7 
Appearance 
Care ............................... 6-45 
Materials 
.................................... 6-53 
Arbit~-ation Program .............................. 8-9 
Ar111rest . Storage ............................... 2-15  Ashtrays 
...................................... 2-49 
Audio Systems ............................. 3-8. 3-12 
Automatic  Headlamp System 
...................... 2-37 
Automatic  Transmission  Check 
...................................... 7-40 
Fluid ....................................... 6-15 
Operation ................................... 2-18 
Park  Mechanism  Check ........................ 7-42 
Shiftin 
...................................... 2-18 
Starting  Your Engine 
.......................... 2-15 
Front ....................................... 6-21 
Rear 
....................................... 6-19 
Axle 
Backglass  Wiper. Blade Replacement 
.............. 6-36 
Battery 
....................................... 6-30 
Charge LiFht ................................ 2-63 
Jump 
Startmg ................................. 5-3 
Replacement,  Keyless 
Entry ..................... 2-8 
Warnings ................................ 5-3, 5-4 
Battery Run-Down  Protection ..................... 2-44 
BBB  Auto 
Line ................................. 8-9 
Better  Business  Bureau  Mediation 
................... 8-9 
Blizzard ...................................... 4-38 
Brake Fluid .................................... 6-27 
9- 1 
ProCarManuals.com 
Page 376 of 386
Climate Control  System ........................... 3-2 
Clock.  Setting 
................................... 3-8 
Comfort  Controls 
................................ 3-2 
Console  Mounted  CD Changer 
.................... 3- 18 
Content Theft-Deterrent 
......................... 2- I 1 
Control  of a Vehicle .............................. 4-6 
ConvenienceNet 
............................... 2-46 
Convex Outside  Mirror 
.......................... 2-42 
Coolant 
.................................. 5-14. 6.21 
Coolant  Heater. Engine .......................... 2- 16 
Courtesy Transportation  ...........................  8-8 
Cruise  Control 
................................. 2-33 
Customer  Assistance  Information 
................... 8- 1 
Customer  Satisfaction  Procedure .................... 8-2 
Compact  Disc  Care 
............................. 3-26 
Dama.  ue. Finish 
............................... 6-52 
Damage.  Sheet  Metal ............................ 6-5 1 
Daytime Running  Lamps ......................... 2-37 
Dead  Battery 
................................... 5-3 
Defects. Reporting  Safety 
........................ 8- IO 
Defensive  Driving ............................... 4-2 
Defrosting 
..................................... 3-6 
Dimensions.  Vehicle 
............................ 6-62 
Dome  Lamps 
.................................. 2-39 
DoorLocks 
..................................... 2-4 
Drive 
........................................ 2-19 
Drive  Axle Service 
.............................. 7-44 
Defogging 
..................................... 3-6  Driver Information  System 
....................... 2-43 
Driver  Position 
................................. i . 12 
Driving 
City 
........................................ 4-31 
Defensive 
.................................... 4-2 
Drunken ..................................... 4-3 
Foreign  Countries 
.............................. 6-5 
Freeway 
.................................... 4-32 
Guidelines 
.................................. 4-14 
Hill and  Mountain  Roads ....................... 4-34 
In a Blizzard ................................. 4-38 
Night 
...................................... 4-27 
Off-Road 
................................... 4-15 
OnCurves  ................................... 
4-9 
Rainy Conditions ............................. 4-28 
Snowy  and  Icy  Conditions 
...................... 4-36 
Through  Deep Standing  Water 
................... 4-30 
WetRoads 
.................................. 4-28 
Winter 
...................................... 4-36 
With 
a Trailer  ................................  4-48 
Driving  On Grades While  Towing 
a Trailer ........... 4-50 
Drunken  Driving 
................................ 4-3 
Electrical  Equipment.  Adding 
............... 3.24. 6.54 
Electrical System 
............................... 6-54 
Electrochomic  Inside Day/Night  Rearview Mirror 
..... 2-40 
Electronic  Level Control 
......................... 4-42 
Engine 
........................................ 6-9 
Coolant  Heater 
............................... 2-16 
Coolant  Level Check 
.......................... 7-39 
Coolant Temperature Gage ..................... 2-66 
9-3 
ProCarManuals.com 
Page 377 of 386
Engine (Continued) .............................. 6-9 
Exhaust 
..................................... 2-24 
FanNoise 
................................... 5-20 
Identification 
................................ 6-54 
OilLevelCheck 
.............................. 7-39 
Overheating 
................................. 5-11 
Specifications 
................................ 6-60 
Engine Compartment Fuse  Block 
.................. 6-58 
Engineoil 
.................................... 6-10 
Adding 
..................................... 6-11 
Additives 
................................... 6-13 
Checking 
................................... 6-11 
Kindtouse 
................................. 6-12 
Pressure Gage 
................................ 2-69 
Used 
....................................... 6-14 
When  to Change 
.............................. 6-  I3 
Exhaust, Engine 
................................ 2-24 
Exit Lighting 
.................................. 2-39 
Express-Down  Window 
.......................... 2-29 
Fabric  Cleaning 
............................... 6-46 
Filling 
a Portable  Fuel Container .................... 6-7 
FillingYourTank 
................................ 6-5 
Fi 1 ter 
Air 
........................................ 6-14 
Remote  Oil .................................. 6- 14 
Finish Care .................................... 6-5 1 
Finish Damage ................................. 6-52 
Running While 
Parked 
......................... 2-25 
Starting 
..................................... 2-15 
Engine Coolant 
................................. 6-2 1 
FirstGear ..................................... 2-20 
Flashers.  Hazard  Warning 
......................... 5-2 
Flat  Tire.  Changing 
............................. 5-21 
Fluids  and Lubricants 
............................ 7-4.5 
FogLampSwitch ............................... 2-38 
Foreign Countries.  Fuel ........................... 6-5 
Four-wheel  Drive 
......................... 2-26. 6-20 
French Language Manual 11 
FrontAxle .................................... 6-21 
Front  Reading Lamps 
....................... 2.39. 2.43 
Front Storage  Area .............................. 2-45 
FrontTowing 
................................... 5-9 
Filling  a Portable Container 
...................... 6-7 
Filling  Your  Tank 
.............................. 6-5 
Foreign  Countries .............................. 6-5 
Engine Compartment 
.......................... 6-58 
Instrument  Panel 
............................. 6-56 
Fuses  and Circuit Breakers 
....................... 6-55 
Gages 
.. ........................... 
Front  Turn  Signal Lamp Bulb Replacement .......... 6-33 
Fuel 
.......................................... 6-3 
Cage 
....................................... 2-72 
Fuse  Block 
Engine Coolant Temperature 
.................... 2-66 
Fuel 
....................................... 2-72 
Engine  Oil Pressure ........................... 2-69 
GasCap 
....................................... 6-5 
Gate  A-jar Light ................................ 2-71 
GAWR 
....................................... 4-40 
Gear 
Positions ................................. 2-18 
9-4 
ProCarManuals.com 
Page 378 of 386
GloveBox .................................... 2-42 
Gross Axle Weight  Rating ........................ 4-40 
Gross Vehicle  Weight  Rating ...................... 4-40 
Guide  en Franpis 
11 .. ................................. 
GVWR ....................................... 4-40 
Halogen  Bulbs 
................................ 6-32 
Hazard  Warning  Flashers 
.......................... 5-2 
Head  Restraints 
................................. 1-5 
Headlamps .................................... 2-36 
Bulb Replacement 
............................ 6-32 
HighLow  Beam Changer 
...................... 2-3 1 
On Reminder ................................ 2-37 
Hearing  Impaired.  Customer  Assistance 
.............. 8-4 
Heated Front  Seats 
............................... 1-3 
Heated Outside  Rearview  Mirror ................... 2-42 
High  Intensity  Discharge Lighting 
.................. 6-3 1 
Highway Hypnosis .............................. 4-34 
Hill  and  Mountain  Roads 
......................... 4-34 
Hitches. Trailer 
................................. 4-46 
Hood 
.......................................... 6-8 
Horn ......................................... 2-29 
Hydroplaning 
.................................. 4-30 
Heating 
........................................ 3-5 
Ignition  Positions 
.................................... 2-14 
Transmission  Lock Check 
...................... 7-42 
Ignition Transmission  Lock Check 
................. 7-42 
Illuminated  Entry 
............................... 2-39 
Inflation. Tire 
............................. 6-37.  7-39  Inflator 
. Accessory .............................. 2-50 
Inspections 
Brakesystem 
................................ 7-44 
Engine Cooling  Systetn 
........................ 7-43 
Exhaust  Systems 
............................. 7-43 
Front Drive Axle  Boot Seal 
..................... 7-43 
Steering 
.................................... 7-43 
Suspension 
.................................. 7-43 
Throttle  System 
.............................. 7-44 
Transfer 
Case ................................ 7-44 
Instrument  Panel 
............................... 2-58 
Cleaning 
.................................... 6-48 
Cluster 
..................................... 2-60 
FuseBlock 
.................................. 6-56 
Interior Lamps  .................................  2-39 
Jacking  Equipment 
............................. 5-24 
Jump  Starting 
................................... 5-3 
Key 
in the  Ignition ............................. 2-11 
Key  Lock  Cylinders  Service 
...................... 7-40 
Keyless  Entry System 
............................ 2-6 
Keys 
.......................................... 2-2 
Labels 
Certification/Tire 
............................. 4-40 
Fuse 
.................................. 6.56.  6.58 
Safety  Belt 
.................................. 1-53 
Service  Parts Identification ..................... 6-54 
Vehicle  Identification  Number 
................... 6-54 
ProCarManuals.com 
Page 379 of 386
Lamps ........................................ 2-36 
Dome 
...................................... 2-39 
Exterior 
.................................... 2-36 
Front  Reading 
........................... 2.39.  2.43 
Interior 
..................................... 2-39 
On  Reminder 
................................ 2-37 
Leaving  Your  Vehicle 
............................. 2-6 
Leaving  Your  Vehicle 
with the Engine  Running ....... 2-22 
Liftgate 
........................................ 2-9 
Manual  Release 
.............................. 2- 10 
Remote  Release .............................. 2- 10 
Lighter ....................................... 2-49 
Lights  Air  Bag  Readiness 
....................... 1-22,  2-63 
Anti-Lock  Brake  System Warning 
............ 2-66? 4-7 
Brake  System  Warning 
......................... 2-65 
Charging  System 
............................. 2-63 
CheckGages 
................................ 2-71 
Gate  Ajar 
................................... 2-7 I 
LowFuel ................................... 2-72 
Safety  Belt  Reminder 
...................... 1-8.2-62 
Security  Warning 
............................. 2-70 
Service4WD 
................................ 2-71 
Service  Engine  Soon 
.......................... 2-67 
Loading  Your  Vehicle 
........................... 4-40 
Locking  Rear  Axle 
.............................. 2-24 
Lockout  Prevention 
.............................. 2-5 
Lockout  Switch 
................................ 2-29 
Locks 
......................................... 2-4 
Door 
........................................ 2-4 
Ignition  Transmission  Check 
.................... 7-42 
Key  Lock  Cylinder  Service 
..................... 7-40 Power  Door 
.................................. 2-5 
Rear  Door  Security 
............................. 2-5 
Loss 
of Control ................................ 4-13 
LowFuelLight 
................................ 2-72 
Lubricants  and  Fluids 
............................ 7-45 
Lubrication  Service 
. Body ........................ 7-40 
Luggagecarrier 
................................ 2-48 
Lumbar  Controls 
................................ 1-3 
Maintenance  Record ........................... 7-47 
Maintenance  Schedule 
............................ 7-1 
Owner Checks and Services ..................... 7-39 
Periodic  Maintenance Inspections 
................ 7-43 
Recommended  Fluids  and  Lubricants 
............. 7-45 
Scheduled  Maintenance  Services 
.................. 7-4 
Long  Trip/Highway 
....................... 7-6. 
7-27 
Short  TripKity 
............................ 7-5. 7-7 
Maintenance.  Underbody 
......................... 6-52 
Malfunction  Indicator  Lamp ...................... 2-67 
Manual  Passenger’s  Seat 
.......................... 1-2 
Methanol 
...................................... 6-4 
Mirrors 
....................................... 2-40 
Convex  Outside 
.............................. 2-42 
Electrocho~nic  Day/Night  Inside  Rearview 
......... 2-40 
Heated  Outside  Rearview 
....................... 2-42 
Illuminated  Visor  Vanity 
....................... 2-50 
Outside 
..................................... 2-42 
Model  Reference 
................................. vi 
Mountain  Roads ................................ 4-34 
Multifunction  Lever 
............................. 2-30 
Maintenance  When  Trailer  Towing 
................. 4-51 
9-6 
ProCarManuals.com 
Page 380 of 386
Net. Convenience .............................. 2-46  Over Things That  Burn ........................ 2-24 
Neutral 
....................................... 2-19 Passing ..................................... 4-12 
New  Vehicle  “Break-In” 
......................... 2- 13 Passlock’ ..................................... 2-12 
Nightvision 
................................... 4-27  Payload ....................................... 4-42 
Normal  Maintenance  Replacement  Parts 
............. 6-6 1 Periodic  Maintenance  Inspections .................. 7-43 
Power 
Odometer 
.................................... 2-6 1 
Off-Road  Driving .............................. 4- 15 
Off-Road  Recovery 
............................. 4- I 1 
OnStar  System ................................ 2-57 
Ordering  Owner  and  Service  Publications 
....... 8- I 1, 8- 12 
Outside Mirror 
Power  Remote Control 
......................... 2-41 
Convex ..................................... 2-42 
Overhead  Console 
.............................. 2-42 
Oil.  Engine 
.................................... 6-10 
Accessory Outlets ............................ 2-52 
DoorLocks 
................................... 2-5 
Remote Control  Mirror 
........................ 2-41 
Seat 
......................................... 1-2 
Steering 
..................................... 4-9 
Steering  Fluid 
................................ 6-25 
Windows 
................................... 2-28 
Pregnancy.  Use  of  Safety Belts 
.................... 1 . 19 
Problems on the  Road 
............................ 5-1 
Publications.  Service  and Owner .............. 8- 1 1. 8. 12 
Overheating  Engine 
............................. 5- 1 1 
Owner Checks  and Services ....................... 7-39  Radiator.  Adding Coolant ....................... 5-17 
Owner  Publications 
........................ 8- I 1. 8- 12  Radiator Pressure  Cap ........................... 6-24 
Radio  Reception 
................................ 3-23 
Paint  Spotting. Chemical  6-52 
Park 
......................................... 2-18 
Shifting  Into  2-21 
Shifting Out 
of 2-23 
AtNight 
2-11 
Brake ...................................... 2-20 
Brake  Mechanism  Check  7-42 
Lots ....................................... 2-11 
On  Hills  with a Trailer 4-50 
Radios ........................ Cassette  Tape Player ........................... 3-8 
Cassette  Tape Player  Care  3.24.  7.39 
CDChanger  3-18 
Compact  Disc Player  3-12 
Compact  Disc Player  Care  3-26 
Rear Seat Audio 
.............................. 3-16 
Setting  the Clock  3-8 
Theft-Deterrent  Feature 
........................ 3-21 
Rain.  Driving  4-28 
................. ................................. ................................. ............................... .......................... Parking ...................... .................................... 
.............................. ....................... 
.................................. ......................... RAP ......................................... 2-15 
9-7 
ProCarManuals.com 
Page 382 of 386
Power ....................................... 1-2 
Rear ........................................ 1-6 
Reclining  Front 
............................... 1-4 
Seats  and Restraint  Systems 
........................ I - 1 
SecondGear ................................... 2-19 
Security Warning Light 
.......................... 2-70 
Service 
4WD Light ............................. 2-7 I 
Service and  Appearance  Care ...................... 6- I 
Service and Owner  Publications .............. 8- 1 1. 8- 12 
Service Engine  Soon Light ....................... 2-67 
Service Parts Identificatmn  Label 
.................. 6-54 
Service  Work, Doing  Your  Own 
.................... 6-2 
Servicing 
Your Air Bag-Equipped  Vehicle ........... 1-27 
Sheet  Metal  Darnage 
............................ 6-5 1 
Shifting ....................................... 2-18 
Out  of Park 
.................................. 2-23 
Signaling Turns 
................................ 2-3 I 
SIR .......................................... 1-20 
Skidding 
...................................... 4-13 
Specifications  and Capacities 
................. 6-60,  6-6 1 
Speedometer ................................... 2-61 
Stains, Cleaning ................................ 6-47 
Starter Switch Check 
............................ 7-4 1 
Starting  Your Engine ............................ 2- 15 
Steam 
........................................ 5-12 
Steering 
In Emergencies ............................... 4- 10 
Power ....................................... 4-9 
Steering  Wheel 
. Tilt ............................. 2-30 
Storage  Compartments ........................... 2-42 
Into Piirk .................................... 2-21 
Speech Impaired.  Customer  Assistance ............... 8-4 Storage. 
Vehicle 
................................ 6-31 
Storing 
a Flat  or  Spare  Tire and Tools ............... 5-29 
Stuck: 
In Sand. Mud. Ice  or  Snow .................. 5-32 
Sun Visors .................................... 2-50 
Sunglasses  Storage 
.............................. 2-45 
Sunroof 
....................................... 2-52 
Supplemental  Inflatable Restraint 
.................. 1-20 
Symbols.  Vehicle .................................. v 
Tachometer .................................. 2-61 
Taillamp Bulb Replacement 
....................... 6-34 
Tape  Player Care 
.......................... 3-247-39 
Theft 
......................................... 2-10 
Thermostat 
.................................... 6-25 
Third  Gear 
.................................... 2-19 
Tilt  Steering  Wheel 
............................. 2-30 
Time. Setting 
................................... 3-8 
Tire Chains 
.................................... 6-44 
Tire  Inflation  Check 
............................. 7-39 
Ti res 
Alignment  and Balance 
........................ 6-43 
Buyin!  New 
................................. 6-40 
Chang~ng  a 
Flat .............................. 5-21 
Cleaning 
.................................... 6-51 
Inflation ............................... 6-37.  7-39 
Inspection  and Rotation 
........................ 6-38 
Pressure 
.................................... 6-37 
Temperature 
................................. 6-42 
Traction 
.................................... 6-42 
Treadwear 
................................... 6-42 
THEFTLOCK 
TM ................................ 3-21 
9-9 
. 
ProCarManuals.com