Reducing Speed While Using Cruise
Control
Press in the button at the end of the lever until you
reach the lower speed you want, then release it.
To slow down in very small amounts, tap the button
briefly. Each time you do this, you’ll go 1 mph (1.6 km/h)
slower.
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.
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.
3-12
This switchbank is located in the center of the instrument
panel.
e(Marker Lamp Defeat Switch):See “Marker Lamp
Defeat Switch” underExterior Lamps on page 3-13.
j(Manual High Idle Switch):See “Manual High Idle
System” underStarting Your Diesel Engine on
page 2-14.
i(Traction Control Switch):SeeTraction Control
System (TCS) on page 4-11.
f(Outside Heated Mirror Switch):SeeOutside
Heated Mirrors on page 2-41.
g(Power Take Off Switch):SeePower Take-Off
(PTO) on page 4-36.
h(Rear Air Suspension Dump Control
Switch):See “Rear Air Suspension Dump Control”
underTwo-Speed Rear Axle Electric Shift Control
on page 2-26.
k(Rear Axle Shift Control Switch):See “Air Shift
Control” (Automatic Transmission) underTwo-Speed
Rear Axle Electric Shift Control on page 2-26.
Exhaust Brake Switch:SeeDiesel Engine Exhaust
Brake on page 2-25.
l(Differential Lock Control Switch):SeeRear
Axle Differential Lock Control on page 4-10.
cd(Air Bag Off Switch):SeeAir Bag Off Switch
on page 1-55.
If your vehicle does not have some of the features
controlled by these switches, there will be a blank switch
marker in its place.
Accessory Power Outlets
With accessory power outlets, you can plug in auxiliary
electrical equipment such as a cellular telephone or
CB radio.
The accessory power outlets are located on the
passenger’s side of the instrument panel.
To use an outlet, pull the cover down. When not using
it, always cover the outlet with the protective cap.
These circuits are protected by a fuse and have
maximum current levels.
Notice:Leaving electrical equipment on for
extended periods will drain the battery. Always turn
off electrical equipment when not in use and do
not plug in equipment that exceeds the maximum
amperage rating.
3-17
Service Transmission Warning Light
If your vehicle has an Allison automatic transmission,
certain transmission malfunctions will turn this light on.
This light is located with
the auxiliary warning lights
in the center of the
instrument panel.
If this light comes on while you are driving, do not use
the transmission shift control or you may lose forward
gears. The computer for the transmission senses
a problem and chooses a gear to stay in so that you
can drive the vehicle in that gear. You may not be able
to drive as fast or back up when this light is on.
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 a GM 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
1000/2000/2200/2400 series automatic transmission, a
lighted bar under the current gear selected will flash.
If your vehicle has an Allison MD 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.
3-31
Rocking Your Vehicle To Get It Out
First, turn your steering wheel left and right. That will
clear the area around your front wheels. If your vehicle
has traction control, you should turn the traction
control system off. SeeTraction Control System (TCS)
on page 4-11. 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 your wheels
in the forward and reverse directions, you will cause
a rocking motion that may free your vehicle. If that does
not get you out after a few tries, you may need to be
towed out. If you do need to be towed out, seeTowing
Your Vehicle on page 4-31.
Using the Tow Hooks
If your vehicle has tow hooks, the hooks are provided at
the front and, on some models, the rear of your
vehicle. You may need to use them if you are stuck
off-road and need to be pulled to some place where you
can continue driving.
4-30
Service............................................................5-3
Doing Your Own Service Work.........................5-4
Two Safety Cautions about Engine Fan
Breakage...................................................5-5
Fuel................................................................5-6
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
Additives.......................................................5-7
Diesel Engine Fuel.........................................5-8
What Fuel to Use...........................................5-8
Very Cold Weather Operation.........................5-10
Water in Fuel...............................................5-10
Running Out of Fuel.....................................5-15
Fuel Filter Replacement.................................5-15
Fuels in Foreign Countries.............................5-16
Filling Your Tank..........................................5-17
Filling a Portable Fuel Container.....................5-18
Checking Things Under the Hood....................5-18
Hood Latches...............................................5-19
Engine Oil (Caterpillar
®Diesel Engine).............5-20
Engine Oil (Gasoline Engine)..........................5-20
Engine Oil (DURAMAX™ Diesel).....................5-25
Engine Air Cleaner/Filter................................5-30
Automatic Transmission Fluid.........................5-31
Manual Transmission Fluid.............................5-32Engine Coolant (Gas and
DURAMAX™ engines)................................5-32
Engine Coolant (Caterpillar
®Diesel Engines).....5-35
Coolant Surge Tank Pressure Cap..................5-35
Engine Overheating.......................................5-36
Cooling System............................................5-38
Engine Fan Noise.........................................5-43
Power Steering Fluid.....................................5-43
Windshield Washer Fluid................................5-44
Brakes........................................................5-46
Battery........................................................5-55
Jump Starting...............................................5-56
Rear Axle.......................................................5-61
Rear Axle Shift Motor....................................5-61
Noise Control System.....................................5-62
Tampering with Noise Control System
Prohibited.................................................5-62
Bulb Replacement..........................................5-63
Replacement Bulbs.......................................5-63
Windshield Wiper Blade Replacement..............5-63
Other Service Items........................................5-64
Fuel Filter....................................................5-64
Primary Fuel Filter and Water Separator..........5-65
Secondary Fuel Filter and Water
Separator/Heater.......................................5-66
Section 5 Service and Appearance Care
5-1
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 all this,
never let your tank get empty.
If you run out of fuel,Running Out of Fuel on page 5-15,
tells you how to restart your engine.
What Fuel to Use
In the United States, for best results use Number 2–D
diesel fuel year-round (above and below freezing
conditions) as oil companies blend Number 2–D fuel to
address climate differences. Number 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 Number
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.
At a minimum, the diesel fuel you use should meet
specifications ASTM D975-02 (Grade Low Sulfur) in the
United States. In addition, the Engine Manufacturers
Association (EMA) has identified properties of an
improved diesel fuel for better engine performance and
durability. Diesel fuels corresponding to the EMA
Recommended Guideline on Premium Diesel Fuel
(FQP-1A) could provide better starting, less noise and
better vehicle performance. If there are questions
about the fuel you are using, contact your fuel supplier.
It is acceptable to use diesel fuel containing up to
5% biodiesel (B5), but the final blended fuel must meet
the same specification, ASTM D975–02 (Grade Low
Sulfur), as other fuels used in your vehicle, and
the biodiesel used for making this fuel must meet the
ASTM D6751–02 specification.
5-8
To inspect the air cleaner/filter, remove the filter from
the vehicle and lightly shake filter to release loose dust
and dirt. If the filter remains “caked” with dirt, a new
filter is required.
{CAUTION:
Operating the engine with the air cleaner/ lter
off can cause you or others to be burned. The
air cleaner not only cleans the air, it helps to
stop ame if the engine back res. If it is not
there and the engine back res, you could
be burned. Do not drive with it off, and be
careful working on the engine with the air
cleaner/ lter off.
Notice:If the air cleaner/ lter is off, a back re can
cause a damaging engine re. And, dirt can
easily get into your engine, which will damage it.
Always have the air cleaner/ lter in place when you
are driving.
Automatic Transmission Fluid
When to Check
A good time to have it checked is when the engine oil is
checked. See your Allison Automatic Transmission
Operator’s Manual to find out when to change your
transmission fluid and filters.
How to Check and What to Use
The Allison Automatic Transmission Operator’s Manual
that came with the vehicle shows how to check the
automatic transmission fluid and what fluid to use.
Automatic Transmission External Filter
Your automatic transmission filter requires periodic
replacement.
Consult the Allison Automatic Transmission Operator’s
Manual that came with the vehicle for proper change
intervals.
5-31
Manual Transmission Fluid
Refer to the Maintenance Schedule to determine how
often to check the lubricant and when to change it. See
Scheduled Maintenance on page 6-5.
Refer to the Maintenance Schedule to determine what
kind of fluid to use. SeePart C: Recommended
Fluids and Lubricants on page 6-29.
When to Check
A good time to have it checked is when the engine oil is
checked. See your Maintenance Schedule to find out
when to change your transmission fluid.
How to Check and What to Use
Check the fluid level only when your engine is off, the
vehicle is parked on a level place and the transmission
is cool enough for you to rest your fingers on the
transmission case.
Then, follow these steps:
1. Remove the filler plug.
2. Check to be sure that the lubricant level is up to the
bottom of the fill opening. On heavy duty
transmissions (an inch of oil level equals about one
gallon of fluid.)
3. If the fluid level is good, install the plug and be sure
it is fully seated. If the fluid level is low, add more
fluid as described in the next steps.
How to Add Fluid
Here’s how to add fluid. Refer to the Maintenance
Schedule to determine the proper fluid to use. SeePart
C: Recommended Fluids and Lubricants on page 6-29.
1. Remove the filler plug.
2. Add fluid at the filler plug hole. Add only enough
fluid to bring the fluid level up to the bottom of the
fill opening.
3. Install the filler plug. Be sure the plug is fully
seated.
Engine Coolant (Gas and
DURAMAX™ engines)
If your vehicle has a Caterpillar®diesel engine, the
Caterpillar®Operation & Maintenance Manual provided
with your vehicle has information regarding the
proper coolant to use.
The cooling system in your vehicle is filled with
DEX-COOL
®engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add
only DEX-COOL
®extended life coolant.
5-32