JEEP WRANGLER 2008 JK / 3.G Owners Manual

NOTE:There is a difference in temperature between the
upper and lower outlets for added comfort. The warmer
air goes to the floor outlets. This feature gives improved
comfort during sunny but cool conditions.
Floor Air is directed through the floor outlets and side
window demist outlets with a small amount
through the defrost outlet.
Mix Air is directed through the floor, defrost and side
window demist outlets. This setting works best in
cold or snowy conditions that require extra heat at
the windshield. This setting is good for maintaining
comfort while reducing moisture on the windshield. Defrost
Air is directed through the windshield and side
window demist outlets. Use this mode with maxi-
mum fan and temperature settings for best windshield
and side window defrosting.
Blower Control
Use this control (center rotary knob) to regulate the
amount of air forced through the system in any mode
you select. The fan speed increases as you move the
control to the right from the OFF position.
Temperature Control
Use this control (right rotary knob) to regulate the
temperature of the air inside the passenger compartment.
The blue area of the scale indicates cooler temperatures
while the red area indicates warmer temperatures.
260 UNDERSTANDING YOUR INSTRUMENT PANEL

Manual Air Conditioning and Heating System — If
Equipped
The controls for the heating/air conditioning and venti-
lation system in this vehicle consist of a series of rotary
knobs. These comfort controls can be set to obtain desired
interior conditions.The instrument panel features four airflow registers. Two
registers are located on the outer ends of the instrument
panel and two are located in the center of the instrument
panel. These registers can be closed to partially block
airflow, and they can be adjusted to direct airflow where
the occupant desires.
Mode Control
The mode control allows you
to choose from several pat-
terns of air distribution. You
can select either a primary
mode, as identified by the
symbols, or a blend of two of
these modes. The closer the
control is to a particular
mode, the more air distribu-
tion you receive from that
mode.
UNDERSTANDING YOUR INSTRUMENT PANEL 261
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PanelAir is directed through the outlets in the instrument
panel. These outlets can be adjusted to direct airflow.
Bi-Level Air is directed through the panel and floor outlets.
NOTE: There is a difference in temperature between the
upper and lower outlets for added comfort. The warmer
air goes to the floor outlets. This feature gives improved
comfort during sunny but cool conditions.
Floor Air is directed through the floor outlets and side
window demist outlets with a small amount
through the defrost outlet.
Mix Air is directed through the floor, defrost and side
window demist outlets. This setting works best in cold or snowy conditions that require extra heat at the
windshield. This setting is good for maintaining comfort
while reducing moisture on the windshield.
Defrost
Air is directed through the windshield and side
window demist outlets. Use this mode with maxi-
mum fan and temperature settings for best windshield
and side window defrosting.
NOTE: The air conditioning compressor operates in
both Mix and Defrost or a blend of these modes even if
the fan switch is not in the A/C position. This dehumidi-
fies the air to help dry the windshield. To improve fuel
economy, use these modes only when necessary.
262 UNDERSTANDING YOUR INSTRUMENT PANEL

Blower Control
Use this control to regulate the
amount of air forced through the
system in any mode you select.
The fan speed increases as you
move the control to the right from
the OFF position.
Temperature Control
Use this control to regulate the
temperature of the air inside the
passenger compartment. The blue
area of the scale indicates cooler
temperatures while the red area
indicates warmer temperatures.NOTE:
If your air conditioning performance seems
lower than expected, check the front of the A/C con-
denser: located in front of the radiator, for an accumula-
tion of dirt or insects. Clean with a gentle water spray
from behind the radiator and through the condenser.
Fabric front fascia protectors may reduce air flow to the
condenser, reducing air conditioning performance.
Recirculation Control
Press this button to choose be-
tween outside air intake or recir-
culation of the air inside the ve-
hicle. A lamp will illuminate when
you are in “Recirculate” mode.
Only use the “Recirculate” mode
to temporarily block out any out-
side odors, smoke, or dust and to
cool the interior rapidly upon ini-
tial start up in very hot or humid weather.
UNDERSTANDING YOUR INSTRUMENT PANEL 263
4

NOTE:Continuous use of the “Recirculate” mode may
make the inside air stuffy and window fogging may
occur. Extended use of this mode is not recommended.
In cold or damp weather, the use of the “Recirculate”
mode will cause windows to fog on the inside because of
moisture buildup inside the vehicle. For maximum de-
fogging, select the Outside Air position.
NOTE: The “Recirculate” mode will not operate in floor,
mix or defrost modes.Air Conditioning
Normal Operation
Press this button to engage the air
conditioning. A lamp will illumi-
nate when the air conditioning
system is engaged. Once the air
conditioning is engaged, use a
combination of the mode control,
fan speed control, and tempera-
ture control to achieve your de-
sired interior temperature.
NOTE: The air conditioning compressor will not engage
until the engine has been running for about 10 seconds.
264 UNDERSTANDING YOUR INSTRUMENT PANEL

MAX A/C
For maximum cooling, select ei-
ther the Panel or Bi-Level position
using the mode control. Then,
press the “A/C” and the “Recir-
culate” buttons so that both lamps
are illuminated, and set the tem-
perature control to its coolest set-
ting.
NOTE:
•Recirculation Mode will not operate in floor, mix or
defrost modes.
•Refer to “Recirculation Control” in this section, for
proper or extended use of this position.
Operating Tips
Window Fogging
Windows will fog on the inside when the humidity inside
the vehicle is high. This often occurs in mild or cool
temperatures when it’s rainy or humid. In most cases
turning on the air-conditioning (pressing the snowflake
button) will clear the fog. Adjust the temperature control,
air direction and blower speed to maintain comfort.
As the temperature gets colder it may be necessary to
direct air onto the windshield. Adjust the temperature
control and blower speed to maintain comfort. Higher
blower speeds will reduce fogging. Interior fogging on
the windshield can be quickly removed by selecting the
defrost mode.
UNDERSTANDING YOUR INSTRUMENT PANEL 265
4

Regular cleaning of the inside of the windows with a
non-filming cleaning solution (vinegar and water works
very well) will help prevent contaminates (cigarette
smoke, perfumes, etc.) from sticking to the windows.
Contaminates increase the rate of window fogging.
Summer Operation
Air conditioned vehicles must be protected with a high
quality antifreeze coolant during summer to provide
proper corrosion protection and to raise the boiling point
of the coolant for protection against overheating. A 50 %
concentration is recommended. Refer to Fluids and
Genuine Parts in Section 7 for the proper coolant type.
When using the air conditioner in extremely heavy traffic
in hot weather especially when towing a trailer, addi-
tional engine cooling may be required. If this situation is
encountered, operate the transmission in a lower gear to
increase engine RPM, coolant flow and fan speed. When
stopped in heavy traffic, it may be necessary to shift intoNEUTRAL (N) and depress the accelerator slightly for
fast idle operation to increase coolant flow and fan speed.
Winter Operation
When operating the system during the winter months,
make sure the air intake, located directly in front of the
windshield, is free of ice, slush, snow, or other obstruc-
tions.
Vacation Storage
Anytime you store your vehicle, or keep it out of service
(i.e., vacation) for two weeks or more, run the air
conditioning system at idle for about five minutes in the
fresh air and high blower setting. This will ensure
adequate system lubrication to minimize the possibility
of compressor damage when the system is started again.
266 UNDERSTANDING YOUR INSTRUMENT PANEL

STARTING AND OPERATING
CONTENTS
Starting Procedures .....................271
▫ Manual Transmission ..................271
▫ Automatic Transmission ................271
▫ Normal Starting ......................271
▫ Extreme Cold Weather (Below –20°F
Or –29°C) ...........................272
▫ If Engine Fails To Start .................273
▫ After Starting ........................274
 Engine Block Heater — If Equipped .........275
Manual Transmission ....................275
▫ Shifting ............................276
▫ Downshifting ........................277
▫ Reverse Shifting ......................278
 Automatic Transmission ..................279
▫ Shift Lock Manual Override ..............279
▫ Brake/Transmission Interlock System .......281
▫ Automatic Transmission With Overdrive .....281
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Four–Wheel Drive Operation (Command-Trac™
Or Rock-Trac™) — If Equipped .............285
▫ Operating Instructions/Precautions .........285
▫ Shift Positions ........................287
▫ Shifting Procedure ....................288
 Trac-Lok™ Rear Axle — If Equipped .........289
 Axle Lock (Tru–Lok™) — Rubicon Models .....290
 Rear Axle Lock — 4WD Non-Rubicon Models
(If Equipped) ..........................291
 Electronic Sway Bar Disconnect — If Equipped . . 292
 On-Road Driving Tips ...................294
 Off-Road Driving Tips ...................294
▫ Side Step Removal — If Equipped .........294
▫ The Basics Of Off-Road Driving ...........296▫
When To Use 4L (Low) Range ............297
▫ Simultaneous Brake And Throttle Operation . . 297
▫ Driving In Snow, Mud And Sand ..........297
▫ Crossing Obstacles (Rocks And Other High
Points) .............................299
▫ Hill Climbing ........................301
▫ Driving Through Water .................304
▫ After Driving Off-Road .................307
 Parking Brake .........................308
 Anti-Lock Brake System ..................309
 Power Steering ........................311
 Tire Safety Information ...................313
▫ Tire Markings ........................313
268 STARTING AND OPERATING

▫Tire Identification Number (TIN) ..........316
▫ Tire Loading And Tire Pressure ...........317
 Tires — General Information ...............321
▫ Tire Pressure .........................321
▫ Tire Inflation Pressures .................322
▫ Tire Pressures For High-Speed Operation ....324
▫ Radial-Ply Tires ......................325
▫ Tire Spinning ........................325
▫ Tread Wear Indicators ..................326
▫ Life Of Tire .........................326
▫ Replacement Tires .....................327
▫ Alignment And Balance .................328
 Tire Chains ...........................329 
Tire Rotation Recommendations ............329
 Tire Pressure Monitor System (TPMS) ........330
▫ Base System .........................333
▫ General Information ...................335
 Fuel Requirements ......................336
▫ Reformulated Gasoline .................336
▫ Gasoline/Oxygenate Blends ..............337
▫ MMT In Gasoline .....................337
▫ Materials Added To Fuel ................338
▫ Fuel System Cautions ..................338
▫ Carbon Monoxide Warnings ..............339
 Adding Fuel ..........................340
▫ Fuel Filler Cap (Gas Cap) ...............340
STARTING AND OPERATING 269
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