
Gasoline Engine Warm-Up
When you have started your engine, let it run for
20 or 30 seconds to warm up before you put a load
on the engine.
Drive at moderate speeds for the first 2 to 3 miles
(3.2 to 4.8 km), especially in cold weather. SeeHigh
Idle System (Caterpillar
®Diesel/Gasoline Engine)
on page 2-19.
Restarting the Gasoline Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, you will first have to shift to NEUTRAL (N).
This safety feature prevents starting the engine when
the transmission is in a drive gear.
Stopping the Gasoline Engine
Let your engine idle for a few seconds before turning it
off after you have finished driving your vehicle.
If you shift to NEUTRAL (N) or PARK (P), set the
parking brake.
If your vehicle has a two-speed axle, put the range
selector in LOW. To be sure the axle has shifted into
LOW, engage the clutch and transmission; the vehicle
may move slightly when you do this.While your engine is idling and before you turn it off,
you can make a list of any operational or handling
concerns to give to responsible maintenance personnel
so they can handle them right away.
Moisture will condense in a fuel tank that is almost
empty if the engine has not run for a while, even just
overnight under some conditions. So, it is always best
to refuel your vehicle at the end of each run.
Starting the Diesel Engine
Your vehicle’s diesel engine starts differently than a
gasoline engine. Read the following pages to learn how
to start, restart, warm-up, and stop your diesel engine.
The information applies to both Caterpillar
®diesel
engine and DURAMAX®diesel engine unless
otherwise noted.
If you have a Caterpillar
®diesel engine, also refer to
your Caterpillar®diesel engine Operation & Maintenance
Manual for the starting procedure.
2-14

If the system senses low engine coolant, the five beat
per second alarm and the low coolant warning light
will come on.
The five beats per second tone alarm means that your
engine will shut down in about 25 to 30 seconds.
There is also an engine shutdown light to indicate that
the engine will shut down. SeeEngine Shutdown
Warning Light on page 3-39.
Pull off the road and shut off the engine. Do not start it
until the reason for the problem is known, and the
problem is fixed. If the engine shuts down when you are
still in traffic, you can restart the engine and get
another 25 to 30 seconds of operation. Do this only if
you have to, since there is a problem that can harm the
engine if it is not fixed. Engine automatic shutdown,
for gasoline engines, requires activation by your dealer.
Notice:If you try to operate the vehicle after the
engine automatically shuts down, you may damage
the vehicle. Have your vehicle repaired as soon
as possible.High Idle System
(Caterpillar
®Diesel/Gasoline Engine)
Automatic High Idle System
(Diesel Engines)
The automatic high idle feature will engage whenever
you start your vehicle and the engine is below the preset
operating temperature. This will help decrease engine
warm-up time.
Idle speed will then return to normal under any of the
following conditions:
•The engine reaches the preset operating
temperature or has been operating for at least
10 minutes.
•The brake pedal is pressed.
•The manual transmission clutch pedal is pressed
or, the automatic transmission (if equipped) is
shifted from NEUTRAL (N) or PARK (P).
•The vehicle speed exceeds about 5 mph (8 km/h).
•The throttle is pressed.
2-19

Exhaust Restrictor
(DURAMAX
®Diesel)
If your vehicle is equipped with a DURAMAX®6600
engine, it has a cold temperature high idle feature which
elevates the engines idle speed from 660 to 1500 rpms,
and restricts the exhaust gas flow, when outside
temperatures are below 32°F (0°C), and the engine
coolant temperature is below 150°F (65°C). This feature
enhances heater performance by raising the engine
coolant temperature faster.
This feature is already turned on. This feature can be
turned off and on by doing the following brake stomp
procedure:
1. Turn the ignition to RUN, with the vehicle off.
2. Press the accelerator pedal to the floor and
hold while quickly pressing the brake pedal
three times in less than eight seconds.
3. Release the accelerator pedal and start
the engine.If this feature is turned on when the engine is started,
the green exhaust brake/restrictor light below the
radio controls will be lit for 10 seconds. If this feature is
turned on and the algorithm comes on, based upon
the temperature conditions and other conditions, then
the green exhaust brake/restrictor light will remain lit and
the engine will slowly ramp up to the high idle speed
after a delay of a few seconds up to approximately
two minutes.
When the engine is started, it will slowly ramp up to the
high idle speed after a delay of a few seconds up to
about two minutes. For this method to work properly
there must be no throttle or brake pedal faults, and the
throttle pedal must not fall below 75 percent of wide
open throttle while pressing the brake pedal.
The engine idle speed will return to normal once the
following conditions are met:
•Once engine coolant temperature reaches
150°F (65°C).
•Air intake temperature reaches 41°F (5°C).
2-21

The high idle speed will be temporarily interrupted and
the engine speed will return to normal if any of the
following conditions occur:
•The brake pedal is applied.
•The accelerator pedal is pressed.
•The automatic transmission is shifted out of
PARK (P) or NEUTRAL (N).
•The clutch pedal on the manual transmission is
pressed.
•Vehicle speed is detected.
Once these inputs are removed, the engine idle speed
will slowly ramp back up to high idle after the normal
delay, if the conditions for engine coolant temperature
and air intake temperature are still met.
If this feature is turned off, by doing the brake stomp
procedure described above, and then the engine
is started the exhaust brake/restrictor light will flash for
10 seconds and then it will turn off.
Engine Checks Before Operating
When you have started your engine, let it run for
20 to 30 seconds before you put a load on the engine.
But do not leave the vehicle while the engine is running.
Avoid unnecessary idling of diesel engine equipped
vehicles.
If the engine idles too long, the temperature of the
engine coolant will fall below the normal operating
range. Low engine operating temperature causes
several conditions which affect engine operation and
reduce engine life.
The engine should be permitted to go through a
warm-up period. Operate the vehicle at a minimum of
600 rpm during the warm-up period. During this
period and during operation, the following observations
should be made.
2-22

During this warm-up period, check your warning lights
and gages:
•If oil pressure does not begin to rise within
15 seconds of starting, stop the engine and find the
cause. SeeOil Pressure Gage on page 3-37for
more information.
•If the engine coolant temperature gage needle goes
into the hot area on the gage, stop the engine and
find the cause of the overheating. SeeEngine
Coolant Temperature Gage on page 3-35for
more information.
•If you have air brakes, the dual-needle air pressure
gage should read at least 115 psi (790 kPa) for
both service systems before you try to move
the vehicle. When air pressure is below 60 psi
(420 kPa), the LOW AIR light will come on and you
will hear a tone alarm. SeeBrake System Warning
Light on page 3-31for more information. If the
pressure does not build up or drops during warm-up,
stop the engine and find the cause before you try
to move the vehicle. Recommended air pressure
before driving is 120 psi (830 kPa). SeeAir
Pressure Gage on page 3-44for more information.
•The charging system light should come on when
the ignition key is turned to RUN or START and
should go out when the engine is running above
idle. If the light does not go out or comes back on
during normal engine operation, have the charging
system checked right away. (This light tells you
if the generator is not charging; it does not reflect
the condition of the battery.) SeeCharging System
Light on page 3-30for more information.
•The voltmeter charge indicator gage tells you the
condition of your battery’s charge. The gage
should be in the center area during engine
operation. The red area on the left indicates an
undercharge condition; the red area on the
right indicates an overcharge. If the gage is in
either red area, have the battery and charging
system checked right away. SeeVoltmeter Gage
on page 3-30for more information.
Notice:Do not allow the engine to operate at low
idle for more than ve minutes. This can cause
low engine operating temperatures which can
affect engine operation and reduce engine life.
Engine idle speed should be increased to 1200 rpm
whenever extended idle is required. Once started,
the engine should be placed under load to allow the
engine coolant temperature to reach 150°F (66°C)
before shutting off the engine.
2-23

Diesel Engine Exhaust Brake
If your vehicle is equipped with a diesel engine,
it may have an exhaust brake, which is located in the
exhaust system.
The exhaust brake is used to help slow the vehicle and
may assist the vehicle’s foundation brakes. The use of
the exhaust brake will assist the braking of the vehicle
and prolong the life of the foundation brake lining
material.
The exhaust brake switch
is located in the instrument
panel switchbank.
Push the bottom of the switch to turn the exhaust brake
on. When you push the top of the switch, the exhaust
brake will turn off.
There is an indicator light on the instrument panel similar
to the symbol on the switch, that will come on when the
exhaust brake is active. SeeExhaust Brake Indicator
Light on page 3-40for more information.When using the exhaust brake, the proper gear range
selection is important. The exhaust brake will be
most effective if the gear range selected is the lowest
possible range that does not allow the engine rpm to go
more than 200 rpm above rated (full load) rpm. If you
have a Caterpillar
®diesel engine, do not exceed
2900 rpm. If you have a DURAMAX®7800 diesel
engine, do not exceed 2550 rpm. If you have a
DURAMAX
®6600 diesel engine, do not exceed
3600 rpm.
If you have an Allison
®1000/2000/2200/2400/2500
series automatic transmission and press this button,
the transmission will downshift to a factory default
setting of fourth gear. To change the default setting,
or for more information on factory default settings,
contact your dealer for assistance.
The accelerator and clutch pedals must be released in
order for the exhaust brake to engage. The exhaust
brake will not function when the cruise control feature
is active with a DURAMAX
®6600 engine, and will
automatically shut off when the anti-lock brake system
is active.
When equipped with a Caterpillar
®diesel engine,
the exhaust brake will become active in cruise control
when you exceed the set speed by 3 mph.
2-25

Air Shift Control
(Automatic Transmission)
The rear axle shift control
switch for an automatic
transmission is located in
the instrument panel
switchbank.
Press the bottom of the switch to get to the low range.
The switch indicator light will come on when the
vehicle is in low range. Press the top of the switch to
return to the high range.
The two-speed axle should be in low range when you
park the vehicle. You will need to engage the
transmission, even moving the vehicle a little, to be sure
the axle is in low range. Then shift into PARK (P),
apply the parking brake and shut off the engine.To shift up from low to high, press the top of the rear
axle shift control switch and press down on the
accelerator. When you shift the axle from high to low,
press the bottom of the switch, release the accelerator
and then quickly press it down again.
To operate off-road or under a heavy load, shift into
low range when the vehicle is standing still and
then operate the transmission normally.
On the highway, with the axle in low range and the
transmission in top gear, you may shift the axle to
high range by raising the switch and releasing
the accelerator momentarily. Re-apply the accelerator
after you shift.
Under light load conditions, first shift the axle into the
high range with the vehicle at a standstill and then
operate the transmission normally.
2-27

During the first 500 miles (805 km) of vehicle use, start
the vehicle moving in FIRST (1) gear. This allows
the clutch components to wear-in properly.
FIRST (1):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into FIRST (1).
Then, slowly let up on the clutch pedal as you press the
accelerator pedal. Only downshift into FIRST (1)
when the vehicle has come to a complete stop. If the
shift lever will not go into FIRST (1), put the lever
in NEUTRAL and let up on the clutch pedal to fully
engage the clutch. Press the clutch pedal again.
Then, shift into FIRST (1).
SECOND (2):With the vehicle at a stop, release the
brake, press the clutch pedal and shift into SECOND (2).
Then, slowly let up on the clutch pedal as you press
the accelerator pedal. With the vehicle moving, press the
clutch pedal and upshift into SECOND (2) from
FIRST (1) while applying light pressure to the right on
the shifter. Then, slowly let up on the clutch pedal
as you press the accelerator pedal. If you come to a
complete stop and the shift lever will not go into
SECOND (2), put the lever in NEUTRAL and let up on
the clutch pedal to fully engage the clutch. Press
the clutch pedal again. Then, shift into SECOND (2).THIRD (3):Press the clutch pedal and upshift into
THIRD (3). Then, slowly let up on the clutch pedal as
you press the accelerator pedal.
FOURTH (4), FIFTH (5) and SIXTH (6):Upshift into
the higher forward gears the same way as you do
THIRD (3). Slowly let up on the clutch pedal as you
press the accelerator pedal.
NEUTRAL:Use this position when you start or idle
your engine.
REVERSE (R):To back up, press the clutch pedal.
Wait for the vehicle to stop moving and then, shift
to REVERSE (R). Let up on the clutch slowly while
pressing the accelerator pedal. Also, use REVERSE (R),
along with the parking brake, when turning off your
engine and parking your vehicle.
2-31