With cruise control, you can maintain a speed
of about 25 mph (40 km/h) or more without
keeping your foot on the accelerator. Cruise
control does not work at speeds below about
25 mph (40 km/h).
If you have an automatic transmission and you
apply your brakes, the cruise control will shut off.
If you have a manual transmission and you
apply your brakes or push the clutch pedal, the
cruise control will shut off.
{CAUTION:
Cruise control can be dangerous where
you cannot drive safely at a steady speed.
So, do not use your cruise control on
winding roads or in heavy traffic.
Cruise control can be dangerous on
slippery roads. On such roads, fast
changes in tire traction can cause
excessive wheel slip, and you could lose
control. Do not use cruise control on
slippery roads.
Setting Cruise Control
{CAUTION:
If you leave your cruise control on when
you are not using cruise, you might hit a
button and go into cruise when you do not
want to. You could be startled and even
lose control. Keep the cruise control switch
off until you want to use cruise control.
1. Move the cruise control switch to on.
2. Get up to the speed you want.
3. Press in the set button at the end of the lever
and release it.
4. Take your foot off the accelerator pedal. The
accelerator pedal will not go down.
147
Passing Another Vehicle While Using
Cruise Control
Use the accelerator pedal to increase your speed.
When you take your foot off the pedal, your
vehicle will slow down to the cruise control speed
you set earlier.
Using Cruise Control on Hills
How well your cruise control will work on hills
depends upon your speed, load and the steepness
of the hills. When going up steep hills, you may
want to step on the accelerator pedal to maintain
your speed. When going downhill, you may
have to brake or shift to a lower gear to keep your
speed down. Of course, applying the brake or
clutch takes you out of cruise control. Many drivers
find this to be too much trouble and don’t use
cruise control on steep hills.
If your vehicle is equipped with the exhaust brake
option and the exhaust brake is turned on, the
exhaust brake may come on and try to slow down
the vehicle to the set cruise control speed if the
vehicle has accelerated past the set cruise control
speed while going downhill.
Ending Cruise Control
There are four different ways to turn off the
cruise control:
•Step lightly on the brake pedal (manual and
automatic transmissions).
•Press the clutch pedal to the floor (manual
transmissions).
•Move the cruise switch to off, or
•Shift the transmission to NEUTRAL (N).
Erasing Speed Memory
When you turn off the ignition, your cruise control
set speed memory is erased.
149
Marker Lamps
If your vehicle has this feature, you can manually
blink the marker and clearance lamps.
The marker lamp defeat
switch is located in the
instrument panel
switchbank.
Press and hold the bottom of the switch to turn off
the marker and clearance lamps. When you
release the switch, the marker and clearance
lamps will come back on.
Instrument Panel Brightness
This feature controls the brightness of the
instrument panel lights.
The thumbwheel for this feature is located to the
right of the exterior lamp control.
Turn the thumbwheel up to brighten the lights.
When the thumbwheel is moved to the first
position, the radio display and transmission
selection display will go to full intensity. The
instrument panel cluster will also be dimly
lit. Moving the thumbwheel up to the next position
will activate the interior dome lamps.
152
This switchbank is located in the center of the
instrument panel.
e(Marker Lamp Defeat Switch):SeeMarker
Lamps on page 152.
j(Manual High Idle Switch):SeeHigh Idle
System on page 106.
i(Traction Control Switch):SeeTraction
Control System (TCS) on page 216.
f(Outside Heated Mirror Switch):SeeOutside
Heated Mirrors on page 134.
g(Power Take Off Switch):SeePower
Take-Off (PTO) on page 118.
h(Rear Air Suspension Dump Control
Switch):Air Suspension on page 129.
k(Rear Axle Shift Control Switch):SeeAir Shift
Control (Automatic Transmission) on page 114.
q(Exhaust Brake Switch):SeeDiesel Engine
Exhaust Brake on page 112.
l(Differential Lock Control Switch):See
Rear Axle Differential Lock Control on page 215.
c(Airbag On/Off Switch):SeeAirbag Off
Switch on page 76.
If your vehicle does not have some of the features
controlled by these switches, there will be a
blank switch marker in its place.
155
Notice:If you continue driving your vehicle
after the transmission warning light comes on,
you could damage the transmission. While
this light is on, the transmission cannot
operate in all gears. If you attempt to shift
gears, the vehicle may not continue to move.
Do not attempt to shift gears while the
transmission warning light is on. Instead, drive
directly to an authorized dealer for service. If
you cannot drive to a dealer immediately, have
the vehicle towed.
Range Inhibit Warning Indicator
If your vehicle has an Allison 1000/2200/2300/
2500 series automatic transmission, a lighted bar
under the current gear selected will flash.
If your vehicle has an Allison 3000/3500
series automatic transmission, the current gear
selected on the pushbutton display will flash.
The flashing bar or gear selection indicates that
transmission range shifts may not occur.
For detailed information on shift inhibit limitations,
see the Allison Automatic Transmission
Operator’s Manual in your vehicle for further
information.
Brake System Warning Light
Your vehicle has either hydraulic or air brakes.
Each system has different warning lights.
Hydraulic Brake System
Warning Lights
Vehicles with hydraulic brake systems
have two brake system warning lights on the
instrument panel.
If the brake system
warning light comes on,
it means that the
fluid level in the master
cylinder reservoir is
low or there is another
problem with your
hydraulic brakes.
When it comes on, you will also hear a
warning tone.
169
If Your Vehicle is Stuck in Sand,
Mud, Ice, or Snow
In order to free your vehicle when it is stuck,
you will need to spin the wheels, but you do not
want to spin your wheels too fast. The method
known as rocking can help you get out when you
are stuck, but you must use caution.
{CAUTION:
If you let your vehicle’s tires spin at high
speed, they can explode, and you or others
could be injured. And, the transmission or
other parts of the vehicle can overheat.
That could cause an engine compartment
re or other damage. When you are stuck,
spin the wheels as little as possible. Do not
spin the wheels above 35 mph (55 km/h)
as shown on the speedometer.
Notice:Spinning the wheels can destroy
parts of your vehicle as well as the tires. If you
spin the wheels too fast while shifting the
transmission back and forth, you can destroy
the transmission.
Rocking Your Vehicle to Get It Out
First, turn the steering wheel left and right.
That will clear the area around the front wheels.
If you have a four-wheel-drive vehicle, shift
into 4HI. SeeFour-Wheel Drive on page 119.
If your vehicle has traction control, you should turn
the traction control system off. SeeTraction
Control System (TCS) on page 216. Then shift
back and forth between REVERSE (R) and
a forward gear, or with a manual transmission,
between FIRST (1) or SECOND (2) and
REVERSE (R), spinning the wheels as little as
possible. Release the accelerator pedal while you
shift, and press lightly on the accelerator pedal
when the transmission is in gear. By slowly
spinning the wheels in the forward and reverse
directions, you will cause a rocking motion
that may free your vehicle. If that does not get
your vehicle out after a few tries, it may need to
be towed out. If your vehicle does need to be
towed out, seeTowing Your Vehicle on page 241.
236
Service........................................................ 248
California Proposition 65 Warning.............. 248
Doing Your Own Service Work.................. 249
Engine Fan Breakage................................ 250
Fuel............................................................. 251
Gasoline Octane........................................ 251
Gasoline Specifications.............................. 251
Additives................................................... 252
Diesel Engine Fuel.................................... 253
What Fuel to Use...................................... 253
Very Cold Weather Operation.................... 256
Water in Fuel............................................ 256
Running Out of Fuel.................................. 262
Fuel Filter Replacement............................. 263
Fuels in Foreign Countries........................ 264
Filling the Tank......................................... 264
Filling a Portable Fuel Container............... 266Checking Things Under the Hood.............. 266
Hood Latches............................................ 267
Engine Oil (Caterpillar
®Diesel Engine)...... 268
Engine Oil (Gasoline Engine).................... 268
Engine Oil (DURAMAX
®/Isuzu Diesel
Engine).................................................. 272
Engine Oil Life System
(Gasoline Engine).................................. 276
Engine Oil Life System
(DURAMAX
®Diesel)............................... 278
Engine Oil Life System
(Caterpillar
®Diesel Engine).................... 279
Engine Air Cleaner/Filter............................ 280
Automatic Transmission Fluid.................... 282
Manual Transmission Fluid........................ 283
Engine Coolant (Gas and
DURAMAX
®/Isuzu Engines).................... 284
Engine Coolant (Caterpillar®Diesel
Engines)................................................ 287
Coolant Surge Tank Pressure Cap............ 288
Section 5 Service and Appearance Care
245
Diesel Engine Fuel
For the Caterpillar®diesel, see the Caterpillar®
Operation & Maintenance Manual for information
concerning fuel usage.
Notice:Diesel fuel or fuel additives not
recommended in this manual could damage
your fuel system and engine. Your warranty
would not cover this damage. And:
Diesel fuel that has been mixed with engine
oil or automatic transmission uid could
damage your engine and emission controls.
Aftermarket diesel fuel additives are not
tested by General Motors. Some additives,
particularly those which contain alcohol or
water emulsi ers, may damage your fuel
system. If you believe that unique
circumstances call for a fuel additive to be
used, consult your dealer for advice.
If you ever run out of diesel fuel, it can be
difficult to restart your engine. To avoid this,
never let your tank get empty.
If gasoline is ever accidentally added to the fuel
tank, to avoid severe engine damage, do not run
the engine until the fuel tank can be drained.
If you run out of fuel,Running Out of Fuel on
page 262tells you how to restart your engine.
What Fuel to Use
In the United States, for best results use
No. 2-D diesel fuel year-round (above and below
freezing conditions) as oil companies blend
No. 2-D fuel to address climate differences.
No. 1-D diesel fuel may be used in very cold
temperatures (when it stays below 0°F or−18°C);
however, it will produce a power and fuel
economy loss. Avoid the use of No. 1-D diesel
fuel in warm or hot climates. It may result in
stalling, poor starting when the engine is hot, and
may damage the fuel injection system.
It is important that diesel-powered trucks are
refueled only with ultra low-sulfur fuel. The
emission control system requires the use of diesel
fuel with ultra low-sulfur (0.0015% by weight, or
15 ppm, maximum) content. Both ultra low-sulfur
and higher sulfur diesel fuels are available in
the United States and ultra low-sulfur diesel fuel is
available in Canada. However, only higher
sulfur diesel fuel is available in Mexico. Use of
fuels with higher-sulfur content will affect the
function of the emission components and may
cause reduced performance, excessive smoke,
and unpleasant odor.
253