
Key In the Ignition
Never leave your vehicle with the keys inside, as it is an
easy target for joy riders or thieves. If you leave the key
in the ignition and park your vehicle, a chime will sound,
when you open the driver’s door. Always remember to
remove your key from the ignition and take it with you.
This will lock your ignition and transaxle. Also, always
remember to lock the doors.
The battery could be drained if you leave the key in the
ignition while your vehicle is parked. You may not be
able to start your vehicle after it has been parked for an
extended period of time.
Retained Accessory Power (RAP)
These vehicle accessories can be used for up to
10 minutes after the engine is turned off:
•Audio System
•Power Windows
These features will work when the ignition key is in
ON/RUN or ACC/ACCESSORY. Once the key is turned
from ON/RUN to LOCK/OFF, power to the radio will
continue to work 10 minutes or until the driver’s door is
opened. The power windows will continue to work for up
to 10 minutes or until any door is opened.
Starting the Engine
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
To place the transmission in the proper gear:
Move your shift lever to PARK (P) or NEUTRAL (N).
Your engine will not start in any other position -- this is
a safety feature. To restart when you are already
moving, use NEUTRAL (N) only.
Starting Procedure
1. With your foot off 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
your engine gets warm. Do not race the engine
immediately after starting it. Operate the engine and
transmission gently to allow the oil to warm up and
lubricate all moving parts.
Your vehicle has a Computer-Controlled Cranking
System. This feature assists in starting the engine
and protects components. If the ignition key is turned
to the START position, and then released when the
engine begins cranking, the engine will continue
cranking for a few seconds or until the vehicle starts.
If the engine does not start and the key is held in
START for many seconds, cranking will be stopped
after 15 seconds to prevent cranking motor damage.
2-20 

To prevent gear damage, this system also prevents
cranking if the engine is already running. Engine
cranking can be stopped by turning the ignition
switch to the ACC/ACCESSORY or LOCK/OFF
position.
Notice:Cranking the engine for long periods of
time, by returning the key to the START position
immediately after cranking has ended, can overheat
and damage the cranking motor, and drain the
battery. Wait at least 15 seconds between each try,
to let the cranking motor cool down.
2. If the engine does not start after 5-10 seconds,
especially in very cold weather (below 0°F or
−18°C), it could be flooded with too much gasoline.
Try pushing the accelerator pedal all the way to the
floor and holding it there as you hold the key in
START for up to a maximum of 15 seconds. Wait at
least 15 seconds between each try, to allow the
cranking motor to cool down. When the engine starts,
let go of the key and accelerator. If the vehicle starts
briefly but then stops again, do the same thing. This
clears the extra gasoline from the engine. Do not
race the engine immediately after starting it. Operate
the engine and transmission gently until the oil
warms up and lubricates all moving parts.Notice:The engine is designed to work with the
electronics in your 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, your
engine might not perform properly. Any resulting
damage would not be covered by your vehicle’s
warranty.
Fuel Regulator
Your vehicle has a fuel regulator that shuts the fuel off
when the engine reaches 5,600 rpm.
Engine Coolant Heater
If your vehicle has the DURAMAX®Diesel engine, see
the DURAMAX®Diesel manual for more information.
The engine coolant heater, if available, can help in cold
weather conditions at or below 0°F (−18°C) for easier
starting and better fuel economy during engine warm-up.
Plug in the coolant heater at least four hours before
starting your vehicle. An internal thermostat in the
plug-end of the cord may exist which will prevent
engine coolant heater operation at temperatures
above 0°F (−18°C).
2-21 

To Use the Engine Coolant Heater
1. Turn off the engine.
2. Open the hood and unwrap the electrical cord.
The cord for the engine coolant heater is located
on the driver’s side of the engine compartment and
is attached to the hose for the power steering
reservoir.
3. Plug it into a normal, grounded 110-volt AC outlet.
{CAUTION:
Plugging the cord into an ungrounded outlet
could cause an electrical shock. Also, the
wrong kind of extension cord could overheat
and cause a  re. You could be seriously
injured. Plug the cord into a properly grounded
three-prong 110-volt AC outlet. If the cord will
not reach, use a heavy-duty three-prong
extension cord rated for at least 15 amps.
4. Before starting the engine, be sure to unplug and
store the cord as it was before to keep it away
from moving engine parts. If you do not, it could be
damaged.How long should you keep the coolant heater plugged
in? The answer depends on the outside temperature, the
kind of oil you have, and some other things. Instead of
trying to list everything here, we ask that you contact your
dealer/retailer in the area where you will be parking your
vehicle. The dealer/retailer can give you the best advice
for that particular area.
Automatic Transmission Operation
There are several different
positions for your shift
lever.
PARK (P):This position locks your rear wheels. It is
the best position to use when you start your engine
because your vehicle cannot move easily.
2-22 

When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a lower
temperature than at normal altitudes. If you turn your
engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating. To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in PARK (P) for a
few minutes before turning the engine off. If you do get
the overheat warning, seeEngine Overheating on
page 5-26.
Parking on Hills
{CAUTION:
You really should not park your vehicle, with a
trailer attached, on a hill. If something goes
wrong, your rig could start to move. People
can be injured, and both your vehicle and the
trailer can be damaged.But if you ever have to park your rig on a hill, here’s
how to do it:
1. Apply your regular brakes, but don’t shift into
PARK (P) yet. Then turn your wheels into the curb if
facing downhill or into traffic if facing uphill.
2. Have someone place chocks under the trailer
wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb the load.
4. Reapply the regular brakes. Then apply your
parking brake and then shift to PARK (P).
5. Release the regular brakes.
When You Are Ready to Leave After
Parking on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
•start your engine,
•shift into a gear, and
•release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the
chocks.
4-40 

Maintenance When Trailer Towing
Your vehicle will need service more often when you’re
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belt, cooling system and brake
system. Each of these is covered in this manual, and the
Index will help you find them quickly. If you’re trailering,
it’s a good idea to review these sections before you start
your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
The optional heavy-duty trailer wiring package includes
a wiring harness, with a seven-pin connector at the
rear of the vehicle and a four-wire harness assembly
under the driver side of the instrument panel. The
four-wire harness assembly comes without a connector.
If your vehicle does not have a trailer hitch, the
seven-wire harness assembly with connector is taped
together and located in a frame pocket at the driver side
rear left corner of the frame.
If your vehicle has a trailer hitch, the seven-wire
harness assembly with connector is attached to a
bracket on the hitch platform. In both cases, the
seven-wire harness has a connector and includes a
30-amp feed wire.
4-41 

Service............................................................5-3
Accessories and Modifications..........................5-3
California Proposition 65 Warning.....................5-3
California Perchlorate Materials Requirements.....5-4
Doing Your Own Service Work.........................5-4
Adding Equipment to the Outside of
Your Vehicle..............................................5-5
Fuel................................................................5-5
Gasoline Octane............................................5-6
Gasoline Specifications....................................5-6
California Fuel...............................................5-6
Additives.......................................................5-7
Fuel E85 (85% Ethanol)..................................5-8
Fuels in Foreign Countries...............................5-9
Filling the Tank............................................5-10
Filling a Portable Fuel Container.....................5-12
Checking Things Under the Hood....................5-12
Hood Release..............................................5-13
Engine Compartment Overview.......................5-14
Engine Oil (Gasoline Engine)..........................5-15
Engine Oil Life System..................................5-18
Engine Air Cleaner/Filter................................5-19
Automatic Transmission Fluid.........................5-20
Engine Coolant.............................................5-23
Radiator Pressure Cap..................................5-26Engine Overheating.......................................5-26
Cooling System............................................5-28
Engine Fan Noise.........................................5-34
Power Steering Fluid.....................................5-34
Windshield Washer Fluid................................5-35
Brakes........................................................5-36
Battery........................................................5-39
Jump Starting...............................................5-40
All-Wheel Drive..............................................5-44
Rear Axle.......................................................5-45
Front Axle......................................................5-45
Noise Control System.....................................5-46
Tampering with Noise Control System
Prohibited.................................................5-46
Bulb Replacement..........................................5-48
Halogen Bulbs..............................................5-48
Headlamps..................................................5-48
Front Turn Signal, Sidemarker and
Parking Lamps..........................................5-50
Center High-Mounted Stoplamp (CHMSL).........5-50
Taillamps.....................................................5-51
Replacement Bulbs.......................................5-52
Windshield Wiper Blade Replacement..............5-52
Section 5 Service and Appearance Care
5-1 

A. Battery. SeeBattery on page 5-39.
B. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-26.
C. Coolant Recovery Tank. SeeCooling System on
page 5-28.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-20.
E. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil (Gasoline Engine) on page 5-15.
F. Engine Oil Dipstick. See “Checking Engine Oil” under
Engine Oil (Gasoline Engine) on page 5-15.
G. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-19.
H. Power Steering Fluid Reservoir. SeePower Steering
Fluid on page 5-34.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-36.
J. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-35.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine Oil” in
the DURAMAX®Diesel manual.
Checking Engine Oil
It is a good idea to check the engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-14for the
location of the engine oil dipstick.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-15 

When to Check and Change Automatic
Transmission Fluid
A good time to check your automatic transmission fluid
level is when the engine oil is changed.
Change the fluid and filter at the intervals listed in
Additional Required Services (Gasoline Engine) on
page 6-6, and be sure to use the transmission fluid listed
inRecommended Fluids and Lubricants on page 6-14.
How to Check Automatic Transmission
Fluid
Because this operation can be a little difficult, you may
choose to have this done at the dealer/retailer service
department.
If you do it yourself, be sure to follow all the instructions
here, or you could get a false reading on the dipstick.
Notice:Too much or too little  uid can damage
your transmission. Too much can mean that some
of the  uid could come out and fall on hot engine
parts or exhaust system parts, starting a  re.
Too little  uid could cause the transmission to
overheat. Be sure to get an accurate reading if you
check your transmission  uid.Wait at least 30 minutes before checking the
transmission fluid level if you have been driving:
•When outside temperatures are above 90°F (32°C).
•At high speed for quite a while.
•In heavy traffic — especially in hot weather.
•While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is 180°F to 200°F
(82°C to 93°C).
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above 50°F
(10°C). If it is colder than 50°F (10°C), drive the vehicle
in DRIVE (D) until the engine temperature gage
moves and then remains steady for 10 minutes.
A cold fluid check can be made after the vehicle has
been sitting for eight hours or more with the engine off,
but this is used only as a reference. Let the engine run
at idle for five minutes if outside temperatures are
50°F (10°C) or more. If it is colder than 50°F (10°C), you
may have to idle the engine longer. Should the fluid level
be low during this cold check, you must check the fluid
hot before adding fluid. Checking the fluid hot will give
you a more accurate reading of the fluid level.
5-21