brake light GMC ENVOY 1999 User Guide

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2-69
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 ªTowing Your Vehicleº
in the Index.)
CAUTION:
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.
If the light stays on, or comes on when you're driving,
your vehicle needs service. 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. See
ªBrake System Warning Lightº earlier in this section.
The anti
-lock brake system warning light should come
on briefly when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
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4-7
Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic. This is a
mistake. Your brakes may not have time to cool between
hard stops. Your brakes will wear out much faster if you
do a lot of heavy braking. If you keep pace with the
traffic and allow realistic following distances, you will
eliminate a lot of unnecessary braking. That means
better braking and longer brake life.
If your engine ever stops while you're driving, brake
normally but don't pump your brakes. If you do, the
pedal may get harder to push down. If your engine
stops, you will still have some power brake assist. But
you will use it when you brake. Once the power assist is
used up, it may take longer to stop and the brake pedal
will be harder to push.
Anti-Lock Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent a braking skid.
When you start your engine and begin to drive away,
your anti
-lock brake system will check itself. You may
hear a momentary motor or clicking noise while this test
is going on. This is normal.
If there's a problem with the
anti
-lock brake system, this
warning light will stay on.
See ªAnti
-Lock Brake
System Warning Lightº in
the Index.
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4-22
CAUTION:
Shifting the transfer case to NEUTRAL can
cause your vehicle to roll even if the transmission
is in PARK (P). This is because the NEUTRAL
position on the transfer case overrides the
transmission. You or someone else could be
injured. If you are going to leave your vehicle, set
the parking brake and shift the transmission to
PARK (P). But do not shift the transfer case to
the NEUTRAL position. Leave the transfer case
in a drive gear.
Driving Downhill
When off-roading takes you downhill, you'll want to
consider a number of things:

How steep is the downhill? Will I be able to maintain
vehicle control?

What's the surface like? Smooth? Rough? Slippery?
Hard
-packed dirt? Gravel?

Are there hidden surface obstacles? Ruts?
Logs? Boulders?
What's at the bottom of the hill? Is there a hidden
creek bank or even a river bottom with large rocks?
If you decide you can go down a hill safely, then try to
keep your vehicle headed straight down, and use a low
gear. This way, engine drag can help your brakes and
they won't have to do all the work. Descend slowly,
keeping your vehicle under control at all times.
CAUTION:
Heavy braking when going down a hill can cause
your brakes to overheat and fade. This could
cause loss of control and a serious accident.
Apply the brakes lightly when descending a hill
and use a low gear to keep vehicle speed
under control.
Q:Are there some things I should not do when
driving down a hill?
A:Yes! These are important because if you ignore
them you could lose control and have a
serious accident.
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4-26 Driving in Water
Light rain causes no special off-road driving problems.
But heavy rain can mean flash flooding, and flood
waters demand extreme caution.
Find out how deep the water is before you drive through
it. If it's deep enough to cover your wheel hubs, axles or
exhaust pipe, don't try it
-- you probably won't get
through. Also, water that deep can damage your axle
and other vehicle parts.
If the water isn't too deep, then drive through it slowly.
At fast speeds, water splashes on your ignition system
and your vehicle can stall. Stalling can also occur if you
get your tailpipe under water. And, as long as your
tailpipe is under water, you'll never be able to start your
engine. When you go through water, remember that
when your brakes get wet, it may take you longer
to stop.
CAUTION:
Driving through rushing water can be dangerous.
Deep water can sweep your vehicle downstream
and you and your passengers could drown. If it's
only shallow water, it can still wash away the
ground from under your tires, and you could lose
traction and roll the vehicle over. Don't drive
through rushing water.
See ªDriving Through Waterº in the Index for more
information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a fire hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust system
for damage. Also, check the fuel lines and cooling
system for any leakage.
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4-29
The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy rain
can make it harder to see road signs and traffic signals,
pavement markings, the edge of the road and even
people walking.
It's wise to keep your wiping equipment in good shape and
keep your windshield washer tank filled with washer fluid.
Replace your windshield wiper inserts when they show signs
of streaking or missing areas on the windshield, or when
strips of rubber start to separate from the inserts.Driving too fast through large water puddles or even
going through some car washes can cause problems, too.
The water may affect your brakes. Try to avoid puddles.
But if you can't, try to slow down before you hit them.
CAUTION:
Wet brakes can cause accidents. They won't work
as well in a quick stop and may cause pulling to
one side. You could lose control of the vehicle.
After driving through a large puddle of water or
a car wash, apply your brake pedal lightly until
your brakes work normally.
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4-54 Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The heavy-duty trailer wiring is an eight-wire harness
assembly. The harness is stored under the vehicle, on the
driver's side corner frame rear crossmember. The
heavy
-duty trailer wiring has a 30-amp feed wire with
an in
-line fuse located by the junction block. See ªFuses
and Circuit Breakersº in the Index. The harness does not
have a connector and should be wired by a qualified
electrical technician. The technician can use the
following color code chart when connecting the wiring
harness to your trailer.

Dark Blue: Use for electric trailer brakes or
auxiliary wiring.
Red: Use for battery charging; it connects to the
starter solenoid.

Light Green: Back
-up lamps.

Brown: Taillamps and parking lamps.

Yellow: Left stoplamp and turn signal.

Dark Green: Right stoplamp and turn signal.

White (Heavy Gauge): Ground wire.

White (Light Gauge): Auxiliary stoplamp.
Securely attach the harness to the trailer, then tape or
strap it to your vehicle's frame rail. Be sure you leave it
loose enough so the wiring doesn't bend or break, but
not so loose that it drags on the ground. Store the
harness in its original place. Wrap the harness together
and tie it neatly so it won't be damaged.
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5-4
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren't touching
each other. If they are, it could cause a ground
connection you don't want. You wouldn't be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake firmly on each vehicle. Put an
automatic transmission in PARK (P) or a manual
transmission in NEUTRAL (N) before setting the
parking brake.
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or the accessory power outlets. Turn off all
lamps that aren't needed as well as radios. This will
avoid sparks and help save both batteries. In
addition, it could save your radio!
NOTICE:
If you leave your radio on, it could be badly
damaged. The repair wouldn't be covered by
your warranty.
4. Open both hoods and locate the batteries. Find the
positive (+) and negative (
-) terminals on each battery.
CAUTION:
Using a match near a battery can cause battery
gas to explode. People have been hurt doing this,
and some have been blinded. Use a flashlight if
you need more light.
Be sure the battery has enough water. You don't
need to add water to the ACDelco Freedom

battery installed in every new GM vehicle. But if
a battery has filler caps, be sure the right amount
of fluid is there. If it is low, add water to take care
of that first. If you don't, explosive gas could
be present.
Battery fluid contains acid that can burn you.
Don't get it on you. If you accidentally get it in
your eyes or on your skin, flush the place with
water and get medical help immediately.
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6-30
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.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly torque wheel nuts in the
proper sequence to GM specifications.
Brake linings should always be replaced as complete
axle sets.
See ªBrake System Inspectionº in Section 7
of this manual under Part C ªPeriodic
Maintenance Inspections.º
Brake Pedal Travel
See your dealer if the brake pedal does not return to
normal height, or if there is a rapid increase in pedal
travel. This could be a sign of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together if
the vehicle is to have really good braking. Your vehicle
was designed and tested with top
-quality GM brake
parts. When you replace parts of your braking
system
-- for example, when your brake linings wear
down and you have to have new ones put in
-- be sure
you get new approved GM replacement parts. If you
don't, your brakes may no longer work properly. For
example, if someone puts in brake linings that are wrong
for your vehicle, the balance between your front and
rear brakes can change
-- for the worse. The braking
performance you've come to expect can change in many
other ways if someone puts in the wrong replacement
brake parts.
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6-59
Name Usage
HORN Horn
BTSI Brake
-Transmission
Shift Interlock
B/U LP Back
-Up Lamps
DRL Daytime Running Lamps
(If Equipped)
IGN B Column Feed, IGN 2, 3, 4
RAP Retained Accessory Power
LD LEV Electronic Load Leveling
OXYSEN Oxygen Sensor
MIR/LKS Mirrors, Door Locks
FOG LP Fog Lamps
IGN E Engine
IGN A Starting and Charging, IGN 1
STUD #2 Accessory Feeds, Electric Brake
PARKLP Parking Lamps
LR PRK Left Rear Parking LampsName Usage
IGN C Starter Solenoid, Fuel Pump,
PRNDL
HTDSEAT Heated Seats
HVAC HVAC System
TRCHMSL Trailer Center High
-Mounted
Stop Light
HIBEAM High
-Beam Headlamps
RRDFOG Rear Defogger
TBC Truck Body Computer
CRANK Clutch Switch, NSBU Switch
HAZLP Hazard Lamps
VECHMSL Vehicle Center High
-Mounted
Stop Lamp
HTDMIR Heated Mirror
ATC Automatic Transfer Case
STOPLP Stoplamps
RR W/W Rear Window Wiper
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9-1
Section 9 Index
A
ccessory Inflator 2-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Accessory Power Outlets 2-57 . . . . . . . . . . . . . . . . . . . . . . . . .
Adding Equipment to the Outside of Your Vehicle 6-3 . . . . . .
Adding Sound Equipment 3-25 . . . . . . . . . . . . . . . . . . . . . . . .
Add-On Equipment 4-44 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Bag
Adding Equipment 1
-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Does it Restrain 1-25 . . . . . . . . . . . . . . . . . . . . . . . . . .
How it Works 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Location 1-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Readiness Light 1-22, 2-67 . . . . . . . . . . . . . . . . . . . . . . . . .
Servicing 1-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System 1-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Conditioning Refrigerants 6-61 . . . . . . . . . . . . . . . . . . . . .
Alignment and Balance, Tire 6-43 . . . . . . . . . . . . . . . . . . . . . .
Aluminum Wheels, Cleaning 6-51 . . . . . . . . . . . . . . . . . . . . . .
Antenna, Fixed 3-27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Anti-Lock Brake System Warning Light 2-69, 4-7 . . . . . . . . .
Anti-Lock Brakes 4-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appearance Care 6-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Appearance Care and Materials 6-53 . . . . . . . . . . . . . . . . . . . .
Arbitration Program 8-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Armrest, Storage 2
-50 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Ashtrays 2-54 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audio Steering Wheel Controls 3-23 . . . . . . . . . . . . . . . . . . . .
Audio Systems 3-8, 3-12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic Headlamp System 2-40 . . . . . . . . . . . . . . . . . . . . . .
Automatic Transmission
Check 7
-40 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid 6-15 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation 2-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Park Mechanism Check 7-42 . . . . . . . . . . . . . . . . . . . . . . . .
Shifting 2-19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting Your Engine 2-16 . . . . . . . . . . . . . . . . . . . . . . . . . .
Axle
Front 6
-20 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Locking Rear 2-32 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear 6-18 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Backglass Wiper, Blade Replacement 6-37 . . . . . . . . . . . . . .
Battery 6-31 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Charge Light 2-67 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jump Starting 5-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacement, Keyless Entry 2-7 . . . . . . . . . . . . . . . . . . . . .
Run-Down Protection 2-43 . . . . . . . . . . . . . . . . . . . . . . . . .
Warnings 5-3, 5-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BBB Auto Line 8-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Better Business Bureau Mediation 8-4 . . . . . . . . . . . . . . . . . . .
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