Page 193 of 398

But the ability to drive is affected well below a BAC of
0.10 percent. Research shows that the driving skills
of many people are impaired at a BAC approaching
0.05 percent, and that the effects are worse at night. All
drivers are impaired at BAC levels above 0.05 percent.
Statistics show that the chance of being in a collision
increases sharply for drivers who have a BAC of
0.05 percent or above. A driver with a BAC level of
0.06 percent has doubled his or her chance of having a
collision. At a BAC level of 0.10 percent, the chance
of this driver having a collision is 12 times greater; at a
level of 0.15 percent, the chance is 25 times greater!
The body takes about an hour to rid itself of the alcohol
in one drink. No amount of coffee or number of cold
showers will speed that up. “I will be careful” is not the
right answer. What if there is an emergency, a need
to take sudden action, as when a child darts into
the street? A person with even a moderate BAC might
not be able to react quickly enough to avoid the
collision.There is something else about drinking and driving that
many people do not know. Medical research shows
that alcohol in a person’s system can make crash
injuries worse, especially injuries to the brain, spinal
cord, or heart. This means that when anyone who has
been drinking — driver or passenger — is in a crash,
that person’s chance of being killed or permanently
disabled is higher than if the person had not been
drinking.
{CAUTION:
Drinking and then driving is very dangerous.
Your re exes, perceptions, attentiveness, and
judgment can be affected by even a small
amount of alcohol. You can have a serious — or
even fatal — collision if you drive after drinking.
Please do not drink and drive or ride with a
driver who has been drinking. Ride home in a
cab; or if you are with a group, designate a
driver who will not drink.
4-5
Page 194 of 398

Control of a Vehicle
You have three systems that make your vehicle go
where you want it to go. They are the brakes, the
steering, and the accelerator. All three systems have
to do their work at the places where the tires meet
the road.
Sometimes, as when you are driving on snow or ice,
it is easy to ask more of those control systems than the
tires and road can provide. That means you can lose
control of your vehicle.
Braking
SeeBrake System Warning Light on page 3-33.
Braking action involves perception time and
reaction time.
First, you have to decide to push on the brake pedal.
That is perception time. Then you have to bring up your
foot and do it. That is reaction time.Average reaction time is about three-fourths of a
second. But that is only an average. It might be less
with one driver and as long as two or three seconds or
more with another. Age, physical condition, alertness,
coordination and eyesight all play a part. So do alcohol,
drugs and frustration. But even in three-fourths of a
second, a vehicle moving at 60 mph (100 km/h) travels
66 feet (20 m). That could be a lot of distance in an
emergency, so keeping enough space between
your vehicle and others is important.
And, of course, actual stopping distances vary greatly
with the surface of the road (whether it is pavement
or gravel); the condition of the road (wet, dry, icy); tire
tread; the condition of your brakes; the weight of
the vehicle; the weight of the load and the amount of
brake force applied.
4-6
Page 195 of 398

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 are driving, brake
normally but do not 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.Hydraulic Brake Systems
If your engine stops running, or if your primary brake
system stops working, your vehicle has a reserve power
assist system to help you slow down. Just slowly and
steadily apply the brake pedal until you can safely get off
the road. The pedal will seem harder to push down.
Do not pump the pedal; the system will not work well or
at all that way.
You may find that the steering wheel seems hard to turn
when you are turning and braking at the same time.
Also, the primary brake warning light may come on and
the warning tone may sound. This is normal because
the main hydraulic brake system and power steering
both use the power steering pump. If this ever happens,
let up on the brake pedal a little. When you let up on
the brake pedal in that situation, it lets the steering get a
little more help from the pump.
4-7
Page 196 of 398
Anti-Lock Brake System (ABS)
Your vehicle has the Anti-Lock Brake System (ABS), an
advanced electronic braking system that will help
prevent a braking skid.
When you start your engine and begin to drive away, ABS
will check itself. You may hear a momentary motor or
clicking noise while this test is going on. This is normal.
If there is a problem with
ABS, this warning light will
stay on. SeeAnti-Lock
Brake System Warning
Light on page 3-35.
Let us say the road is wet and you are driving safely.
Suddenly, an animal jumps out in front of you. You slam
on the brakes and continue braking. Here is 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 wheel.
4-8
Page 197 of 398

ABS 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.Remember: ABS does not change the time you need to
get your foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle
in front of you, you will not have time to apply your
brakes if that vehicle suddenly slows or stops. Always
leave enough room up ahead to stop, even though
you have ABS.
Using ABS
Do not pump the brakes. Just hold the brake pedal
down firmly and let anti-lock work for you. You may feel
the brakes pulsate, or you may hear air exhausting if
you have air brakes, but this is normal.
Braking in Emergencies
With ABS, you can steer and brake at the same time. In
many emergencies, steering can help you more than
even the very best braking.
4-9
Page 198 of 398
Trailer Brake Hand Control Valve
If your vehicle has this feature, the control is mounted
on the floor console.
This feature lets you apply
the trailer brakes without
applying the tractor brakes.
You can apply the trailer brakes a little or apply them all
the way if you have to. Use this control only when
you are driving. Do not use it for parking or to hold the
rig on a hill.{CAUTION:
Using the trailer brake hand control for parking
or for holding the vehicle on a hill may not
keep the vehicle from rolling. This can happen
if someone hits the valve by accident, or if air
pressure bleeds from the system. If the vehicle
rolls, you or others could be injured. To park
the vehicle or hold it on a hill, use the parking
brake properly.
4-10
Page 199 of 398

Rear Axle Differential Lock Control
If your vehicle has a
controlled traction or
locking differential axle,
the switch is located in the
center of the instrument
panel.
You’ll see this control on single rear axle vehicles.
If you’re approaching a slippery surface where it looks
like one or even both wheels may start to slip, you
can press the bottom of this switch. It locks your rear
differential so that power is transmitted equally to
both rear wheels.Let up on the accelerator before you turn on your rear
axle differential lock.
Notice:Turning on the inter-axle differential lock
while the rear wheels are spinning freely, as
they might on snow or ice, can damage the axle(s).
Turn on this control only while the wheels are
not spinning freely.
Wheel Differential Lock
This switch is located on
the center instrument
panel.
Press the switch to engage/lock the tandem front axle
differential to the rear axle differential. This driver
controlled feature improves traction over slippery or
uneven surfaces.
4-11
Page 200 of 398

Traction Control System (TCS)
Your vehicle may have a traction control system that
limits wheel spin. This is especially useful in slippery
road conditions. The system operates only if it senses
that one or both of the rear wheels are spinning or
beginning to lose traction. When this happens,
the system applies the brake(s) at the affected wheel(s).
The bottom light on the TCS on/off button will come
on when the TCS is limiting wheel spin. You may feel or
hear the system working, but this is normal. The TCS
will function at speeds up to about 25 mph (42 km/h).
The TCS may operate on dry roads under some
conditions. When this happens, you may notice a
reduction in acceleration. This is normal and doesn’t
mean there’s a problem with your vehicle. Examples of
these conditions include a hard acceleration in a
turn, an abrupt upshift or downshift of the transmission
or driving on rough roads.When the light in the top of the TCS button is on, the
TCS is off and will not limit wheel spin. Adjust your
driving accordingly.
The light in the top of the TCS button will come on if the
TCS is turned off by pressing the TCS on/off button.
The light may also come on if a problem has been
detected in either the traction control system or
the anti-lock brake system.
The traction control system automatically comes on
whenever you start your vehicle. To limit wheel
spin, especially in slippery road conditions, you should
always leave the system on. But you can turn the
traction control system off if you ever need to. You
should turn the system off if your vehicle ever gets stuck
in sand, mud or snow and rocking the vehicle is
required. SeeRocking Your Vehicle to Get It Out on
page 4-32for more information.
4-12