1999 CHEVROLET EXPRESS ABS

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 Brake System (ABS)
Your vehicle has anti-lock brakes. 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.

4-8
Let's say the road is wet and you're driving safely.
Suddenly, an animal jumps out in front of you.
You slam on the brakes and continue braking.
Here's what happens with ABS:
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at
both rear wheels.The anti
-lock system can change the brake pressure faster
than any driver could. The computer is programmed to
make the most of available tire and road conditions.
This can help you steer around the obstacle while
braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.

4-14
If your vehicle starts to slide, ease your foot off the
accelerator pedal and quickly steer the way you want
the vehicle to go. If you start steering quickly enough,
your vehicle may straighten out. Always be ready for a
second skid if it occurs.
Of course, traction is reduced when water, snow, ice,
gravel or other material is on the road. For safety, you'll
want to slow down and adjust your driving to these
conditions. It is important to slow down on slippery
surfaces because stopping distance will be longer and
vehicle control more limited.
While driving on a surface with reduced traction,
try your best to avoid sudden steering, acceleration
or braking (including engine braking by shifting to a
lower gear). Any sudden changes could cause the tires
to slide. You may not realize the surface is slippery until
your vehicle is skidding. Learn to recognize warning
clues
-- such as enough water, ice or packed snow on
the road to make a ªmirrored surfaceº
-- and slow down
when you have any doubt.
Remember: Any anti
-lock brake system (ABS) helps
avoid only the braking skid.
Driving at Night
Night driving is more dangerous than day driving.
One reason is that some drivers are likely to be
impaired
-- by alcohol or drugs, with night vision
problems, or by fatigue.

4-41 Parking on Hills
CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People can
be injured, and both your vehicle and the trailer
can be damaged.
But if you ever have to park your rig on a hill, here's
how to do it:
1. Apply your regular brakes, but don't shift into
PARK (P) yet. Then turn your wheels into the curb
if facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your parking
brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:

start your engine,

shift into a gear, and

release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
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.

6-65
POSITION NAME CIRCUITS PROTECTED
14. ILLUM Instrument Panel Cluster, HVAC Controls, RR HVAC Controls,
Instrument Panel Switches, Radio Illumination,
Door Switch Illumination
15. DRL Daytime Running Lamp Relay
16. TURN B/U
Front Turn, RR Turn, Back
-up Lamps, BTSI Solenoid
17.
RADIO
-1Radio (Ign, Accy), Upfitter Provision Relay
18. BRAKE 4WAL PCM, ABS, Cruise Control
19.
RADIO
-BRadio (Battery), Power Antenna
20. TRANS PRNDL, Automatic Transmission
21. SECURITY Passlock
22. RR DEFOG Rear Window Defog
23. NOT USED Not Used
24. RR HVAC RR HVAC Controls, HIGH, MED, LOW Relays
A. PWR ACCY
Power Door Lock, Six
-Way Power Seat, Keyless Entry
Illumination Module
B. PWR WDO Power Windows

6-66 Engine Compartment Fuse Block
The fuse block is in the engine compartment on the
driver's side of the vehicle.
NAME CIRCUITS PROTECTED
SPARE Spare Fuse
A.I.R. Air Pump
BLOWER Front Blower Motor
ABS Electronic Brake Control Module
IGN B Ignition Switch
IGN A Starter Relay, Ignition Switch
BATT Instrument Panel Fuse Block
LIGHTING Instrument Panel Fuse Block,
Headlamp Switch
RH
-HDLP Right-hand Headlamp
(Export only)
LH
-HDLP Left-hand Headlamp
(Export only)
RH
-HIBM Right-hand High-beam Headlamp
(Export only)
LH
-HIBM Left-hand High-beam Headlamp
(Export only)

6-67
NAME CIRCUITS PROTECTED
ETC Electronic Throttle Control
RR BLOWER Rear Auxiliary Blower
Motor Relays
CNG Compressed Natural Gas
ENG
-I Heated O2 Sensors, Mass Air
Flow Sensor, Evap Canister Purge
Valve, Crankshaft Position Sensor,
Secondary Air Injection Relay
(Diesel), Water in Fuel Sensor
(Diesel), Fuel Heater (Diesel),
Glowplug Relay (Diesel),
Wastegate Solenoid (Diesel)
ECM
-I Ignition Coil, Camshaft Position
Sensor, VCM, Fuel Injectors,
Coil Driver
IGN
-E Air Conditioning Clutch Relay
SPARE Spare Fuse
SPARE Spare Fuse
SPARE Spare FuseNAME CIRCUITS PROTECTED
A/C Air Conditioning Clutch Relay
HORN Horn Relay, Underhood Lamp(s)
ECM
-B Fuel Pump Relay, VCM, PCM,
Fuel Pump and Engine Oil
Pressure Switch
SPARE Spare Fuse
SPARE Spare Fuse
AUX A Upfitter Provisions
AUX B Upfitter Provisions
A/C RELAY Air Conditioning
HORN RELAY Horn
A.I.R. RELAY Air
FUEL
PUMP RELAYFuel Pump
STARTER
RELAYStarter
ABS EXPORT
RELAYABS Export