
Q:Because I have a disability, I have to get my
vehicle modified. How can I find out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
The phone numbers and addresses for Customer
Assistance are in Step Two of the Customer
Satisfaction Procedure in this manual. See
Customer Satisfaction Procedure on page 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag sensors,
sensing and diagnostic module and airbag wiring.
Restraint System Check
Checking the Restraint Systems
Safety Belts
Now and then, check the safety belt reminder light,
safety belts, buckles, latch plates, retractors, and
anchorages are all working properly.
Look for any other loose or damaged safety belt system
parts that might keep a safety belt system from doing
its job. See your dealer/retailer to have it repaired.Torn or frayed safety belts may not protect you in a
crash. They can rip apart under impact forces. If a belt
is torn or frayed, get a new one right away.
Make sure the safety belt reminder light is working. See
Safety Belt Reminders on page 3-26for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-89.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness Light
on page 3-27for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly. Do
not open or break the airbag coverings. If there are
any opened or broken airbag covers, have the
airbag covering and/or airbag module replaced. For
the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-53. See your
dealer/retailer for service.
1-59

Ignition Positions
The ignition switch has five different positions.
A (ACC/ACCESSORY):This position allows you to use
the radio, power windows and the windshield wipers
when the engine is off. To get into ACC/ACCESSORY,
push in the key and turn it toward you. The steering
wheel will remain locked, just as it was before you
inserted the key.
B (LOCK):This position locks the ignition, steering
wheel and transmission. You will only be able to remove
the key when the ignition is turned to LOCK.C (OFF):This position turns off the engine, but leaves
the steering wheel unlocked. Use OFF if you must
have the vehicle in motion while the engine is off.
D (ON/RUN):This position can be used to operate the
electrical accessories and to display some instrument
panel cluster warning and indicator lights. The
switch stays in this position when the engine is running.
If you leave the key in the ACC/ACCESSORY or
ON/RUN position with the engine off, the battery could
be drained. You may not be able to start the vehicle
if the battery is allowed to drain for an extended period
of time.
E (START):This is the position that starts the engine.
When the engine starts, release the key. The ignition
switch returns to ON/RUN for driving.
A warning tone will sound when the driver door is
opened, the vehicle is parked, and the key is in the
ignition.
2-11

Starting the Engine
1. Without pushing the accelerator pedal, turn the
ignition key to START. When the engine starts,
let go of the key. The idle speed will go down as the
engine gets warm.
2. If the engine does not start in 10 seconds, push the
accelerator pedal all the way down and crank the
engine for five more seconds, unless it starts sooner.
3. If the engine still will not start, or starts but then
stops, it could be flooded with too much gasoline.
Wait 15 seconds to let the starter motor cool down.
Do Steps 1 through 3 again.
When the engine starts, let go of the key and the
accelerator pedal.
Notice:The engine is designed to work with the
electronics in the vehicle. If you add electrical parts
or accessories, you could change the way the
engine operates. Before adding electrical equipment,
check with your dealer/retailer. If you do not, the
engine might not perform properly. Any resulting
damage would not be covered by the vehicle
warranty.
If you ever need to have the vehicle towed, seeTowing
Your Vehicle on page 4-23.
Gasoline Engine Warm-Up
When the engine starts, let it run for 20 or 30 seconds
to warm up before putting a load on it.
Drive at moderate speeds for the first 2 to 3 miles
(3.2 to 4.8 km), especially in cold weather. SeeHigh
Idle System on page 2-20.
Restarting the Gasoline Engine While
Moving (Automatic Transmission)
If you have to restart the engine while the vehicle is
moving, shift to N (Neutral).
Stopping the Gasoline Engine
Let the engine idle for a few seconds before turning it
off after you have finished driving the vehicle.
If you shift to N (Neutral) or P (Park), set the parking
brake.
If the 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 the 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.
2-13

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 the vehicle at the end of each run.
Starting the Diesel Engine
The vehicle’s diesel engine starts differently than a
gasoline engine. Read the following pages to learn how
to start, restart, warm-up, and stop the diesel engine.
The information applies to Caterpillar
®Diesel Engine,
6.6L DURAMAX®Diesel Engine, Isuzu 6H Diesel
Engine, unless otherwise noted.
If you have a Caterpillar
®Diesel Engine, also refer to
the Caterpillar®Diesel Engine Operation & Maintenance
Manual for the starting procedure.
Automatic Transmission
Move the shifter to P (Park) or N (Neutral). The engine
will not start in any other position. To restart the
engine when the vehicle is already moving, use
N (Neutral) only.
Notice:Do not try to shift to P (Park) if the
vehicle is moving. If you do, you could damage
the transmission. Shift to P (Park) only when
the vehicle is stopped.
Manual Transmission
Move the shift lever to N (Neutral) and hold the clutch
pedal to the floor while starting the engine. The vehicle
will not start if the clutch pedal is not all the way down.
Starting the Engine
1. Turn your ignition key to ON/RUN.
Observe the wait to start light. SeeWait to Start
Light on page 3-35. This light may not come
on if the engine is hot.
If you have a Caterpillar
®diesel engine, see your
Caterpillar®Diesel Engine Operation & Maintenance
Manual for proper wait to start light operation.
2. As soon as the wait to start light goes off,
immediately turn the ignition key to START.
When the engine starts, let go of the key.
If the vehicle is equipped with a DURAMAX
®
6600 Diesel Engine, it has a fast warm-up glow
plug system. The wait to start light will illuminate for
a much shorter time than most diesel engines,
due to the rapid heating of the glow plugs.
Notice:Holding the key in START for longer than
15 seconds at a time will cause the battery to
be drained much sooner. And the excessive heat
can damage the starter motor.
2-14

Notice:If the wait to start light stays on after
starting the vehicle, the vehicle may not run
properly. Have the vehicle serviced right away.
3. If the engine does not start after 15 seconds
of cranking, turn the ignition key to OFF. Wait one
minute for the starter to cool, then try the same
steps again.
If you are trying to start the engine after you have run
out of fuel, seeRunning Out of Fuel on page 5-17.
When the engine is cold, let it run for a few minutes
before you move the vehicle. This lets oil pressure build
up. The engine will sound louder when it is cold.
Notice:If you are not in an idling vehicle and the
engine overheats, you would not be there to see the
overheated engine indication. This could damage
the vehicle. Do not let the engine run when you are
not in the vehicle.
Cold Weather Starting
If the vehicle has the 6.6L DURAMAX®Diesel Engine or
the Isuzu 6H Diesel Engine, the following notice applies:
Notice:The diesel engine has an electric air intake
heater system which reduces white smoke and
helps start the engine in cold weather. Do not spray
starting fluid into the air intake where it can
contact the heater elements.If you do not have the GM Automatic Ether Injection
System, do not use starting fluid or you could
damage the engine. If you have the GM system, use
only GM approved starting fluid that has been tested
to establish compatibility with the air inlet heater
system.
The following tips will help with engine starting in cold
weather.
•Use the recommended engine oil when the outside
temperature drops below freezing. SeeEngine Oil
(DURAMAX Diesel Engine) on page 5-24or
Engine Oil (Caterpillar Diesel Engine) on page 5-27
orEngine Oil (Isuzu Diesel Engine) on page 5-28
orEngine Oil (Gasoline Engine) on page 5-32.
When the outside temperature drops below
0°F (−18°C), use of the optional engine coolant
heater is recommended.
•If you experience longer cranking times, notice an
unusual amount of exhaust smoke or are at
higher altitudes (over 7,000 ft. or 2 135 m), you may
use the optional engine coolant heater. See
Engine Coolant Heater on page 2-25.
•SeeWhat Fuel to Use on page 5-8for information
on what fuel to use in cold weather.
2-15

If the Diesel Engine Will Not Start
If you have run out of fuel, seeRunning Out of Fuel on
page 5-17.
If you are not out of fuel, and the engine will not start,
do this:
Turn the ignition key to ON/RUN. Immediately after the
wait to start light goes off, turn the ignition key to START.
If the light does not go off, wait a few seconds, then try
starting the engine again. And, see your dealer/retailer
as soon as you can for a starting system check.
If the light comes on and then goes off and you know
the batteries are charged, but the engine still will
not start, the vehicle needs service.
If the light does not come on when the engine is cold,
the vehicle needs service.If the batteries do not have enough charge to start the
engine, seeBattery on page 5-61.
Be sure you have the right oil for the engine, and that
you have changed the oil at the proper times. If you use
the wrong oil, the engine may be harder to start.
Be sure you are using the proper fuel for existing
weather conditions. SeeWhat Fuel to Use on page 5-8.
If the engine starts, runs a short time, then stops, the
vehicle needs service.
{CAUTION:
Do not use gasoline or starting aids, such as
ether, in the air intake. They could damage the
engine. There could also be a fire, which could
cause serious personal injury.
2-17

Engine Alarm and Automatic
Shutdown
The check gages warning light will come on if the
system senses high engine temperature, and a low or
high engine oil pressure. If high engine temperature,
low engine oil pressure or high engine oil pressure
is detected, you will hear a tone alarm at two beats per
second. The alarm and the light will remain on until
the condition is fixed. If the engine temperature or oil
pressure condition worsens, the tone alarm will go to
five beats per second.
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 the
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 3-40.
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 another25 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/retailer.
Notice:If you try to operate the vehicle after the
engine automatically shuts down, you may damage
the vehicle. Have the vehicle repaired as soon as
possible.
Ambulance, Fire, and Rescue Packages
The check gages warning light will come on if the
system senses high engine temperature or low engine
oil pressure. If high engine temperature or low engine oil
pressure is detected, you will also hear a tone alarm
at two beats per second. The alarm and the light
will remain on until the condition is fixed. If the engine
temperature or oil pressure condition worsens, the
tone alarm will go to five beats per second.
If the system senses low engine coolant, the five beat
per second alarm and the low coolant warning light
will come on.
The engine will not shutdown, but you should have the
vehicle checked as soon as you can. SeeCheck
Gages Warning Light on page 3-43for more information.
2-18

The ENGINE SHUTDOWN WARNING LIGHT will come
on and a continuous chime will alert the driver
30 seconds before the engine goes into idle shutdown
mode. The engine shutdown warning light and chime will
stay on for the entire duration of the idle shutdown
event to inform the driver that the engine is in idle
shutdown mode. SeeEngine Shutdown Warning Light
on page 3-40for more information.
After the engine shutdown occurs, the engine is no
longer running, and the ignition is still in the ON/RUN
position, all accessories can be used. Turn the ignition
switch to START to restart the engine or turn it to
LOCK or OFF to prevent the battery from draining.High Idle System
High Idle System with Switch
If the vehicle has this
feature, the manual high
idle switch is located in the
instrument panel
switchbank.
2-20