wheel JEEP WRANGLER 2008 Owners Manual

INTRODUCTION
This is a specialized utility vehicle designed for both
on-road and off-road use. It can go places and perform
tasks for which conventional two-wheel drive enclosed
vehicles were not intended. It handles and maneuvers
differently from many passenger cars both on-road and
off-road, so take time to become familiar with your
vehicle.
The two-wheel drive utility vehicle was designed for
on-road use only. It is not intended for off-road driving
or use in other severe conditions suited for a four-wheel
drive vehicle.
Before you start to drive this vehicle, read the Owner’s
Manual. Be sure you are familiar with all vehicle controls,
particularly those used for braking, steering, transmis-
sion, and transfer case shifting. Learn how your vehicle
handles on different road surfaces. Your driving skills
will improve with experience. When driving off-road orworking the vehicle, don’t overload the vehicle or expect
the vehicle to overcome the natural laws of physics.
Always observe federal, state, provincial and local laws
wherever you drive.
As with other vehicles of this type, failure to operate this
vehicle correctly may result in loss of control or an
accident. Refer to “On-Road/Off-Road Driving Tips” in
Section 5 of this manual.
This manual has been prepared with the assistance of
service and engineering specialists to acquaint you with
the operation and maintenance of your vehicle. It is
supplemented by a Warranty Information Booklet and
various customer-oriented documents. You are urged to
read these publications carefully. Following the instruc-
tions and recommendations in this manual will help
assure safe and enjoyable operation of your vehicle.
4 INTRODUCTION

Key-In-Ignition Reminder
Opening the driver’s door when the key is in the ignition,
sounds a signal to remind you to remove the key.
STEERING WHEEL LOCK
Your vehicle is equipped with a passive steering wheel
lock. This lock prevents steering the vehicle without the
ignition key. If the steering wheel is moved a half turn in
either direction, and the key is not in the ignition, the
steering wheel will lock.
To Manually Lock the Steering Wheel
With the engine running, rotate the steering wheel one–
half revolution from the straight ahead position, turn off
the engine, and remove the key. Rotate the steering wheel
slightly in both directions until the lock engages.
To Release the Steering Wheel Lock
Insert the key in the ignition, and turn the wheel slightly
to the left or right, to disengage the lock.
NOTE:If you turned the wheel to the right to engage
the lock, you must turn the wheel slightly to the right to
disengage it. If you turned the wheel to the left to engage
the lock, turn the wheel slightly to the left to disengage it.
SENTRY KEY
The Sentry Key Immobilizer System prevents unautho-
rized vehicle operation by disabling the engine. The
system does not need to be armed or activated. Operation
is automatic, regardless of whether the vehicle is locked
or unlocked.
The system uses ignition keys that have an embedded
electronic chip (transponder) to prevent unauthorized
vehicle operation. Therefore, only keys that are pro-
grammed to the vehicle can be used to start and operate
14 THINGS TO KNOW BEFORE STARTING YOUR VEHICLE

WARNING!
Tilting the steering column while the vehicle is
moving is dangerous. Without a stable steering col-
umn, you could lose control of the vehicle and have
an accident. Adjust the column only while the ve-
hicle is stopped. Be sure it is locked before driving.
ELECTRONIC SPEED CONTROL — IF EQUIPPED
When engaged, this device takes over the accelerator
operation at speeds greater than 35 mph (56 km/h). The
speed control lever is located on the right side of the
steering wheel.
To Activate
Push the ON/OFF button. The Cruise Indicator Light in
the instrument cluster will illuminate. To turn the system
OFF, push the ON/OFF button a second time. The Cruise
Indicator Light will turn off. The system should be
turned OFF when not in use.

WARNING!
ABS (Anti-Lock Brake System) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
road conditions. ABS cannot prevent accidents, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. Only a safe, attentive, and skillful driver can
prevent accidents. The capabilities of an ABS-
equipped vehicle must never be exploited in a reck-
less or dangerous manner which could jeopardize the
user’s safety or the safety of others.
TCS (Traction Control System)
This system monitors the amount of wheel spin of each of
the driven wheels. If wheel spin is detected, brake
pressure is applied to the slipping wheel(s) to provide
enhanced acceleration and stability. A feature of the TCS
system functions similar to a limited slip differential and
controls the wheel spin across a driven axle. If one wheel
on a driven axle is spinning faster than the other, the
system will apply the brake of the spinning wheel. This
will allow more engine torque to be applied to the wheel
that is not spinning. This feature remains active even if
TCS and ESP are in either the “Partial Off” or “Full Off”
modes. Refer to “ESP (Electronic Stability Program)” in
this section.
106 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

ERM (Electronic Roll Mitigation)
This system anticipates the potential for wheel lift by
monitoring the driver ’s steering wheel input and the
speed of the vehicle. When ERM determines that the rate
of change of the steering wheel angle and vehicles speed
are sufficient to potentially cause wheel lift, it applies the
appropriate brake and may reduce engine power to
lessen the chance that wheel lift will occur. ERM will only
intervene during very severe or evasive driving maneu-
vers.
ERM can only reduce the chance of wheel lift occurring
during severe or evasive driving maneuvers. It cannot
prevent wheel lift due to other factors such as road
conditions, leaving the roadway or striking objects or
other vehicles.NOTE:
Anytime the ESP system is in the “Full Off”
mode, ERM is disabled. Refer to ESP (Electronic Stability
Program) for a complete explanation of the available ESP
modes.

WARNING!
ESP (Electronic Stability Program) cannot prevent the
natural laws of physics from acting on the vehicle,
nor can it increase the traction afforded by prevailing
road conditions. ESP cannot prevent accidents, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. Only a safe, attentive, and skillful driver can
prevent accidents. The capabilities of an ESP-
equipped vehicle must never be exploited in a reck-
less or dangerous manner which could jeopardize the
user’s safety or the safety of others.
The ESP system has three available operating modes in
4H range. The system has one operating mode in 4L
range. 2WD vehicles and 4WD vehicles in 2H range have
two operating modes.
4H Range (4WD Models) or 2WD Models
On
This is the normal operating mode for ESP in 4H and
2WD vehicles. Whenever the vehicle is started or the
transfer case (if equipped) is shifted from 4L range or
NEUTRAL back to 4H range, the ESP system will be in
this mode. This mode should be used for most all driving
situations. ESP should only be turned to “Partial Off” or
“Full Off” for specific reasons as noted below.
Partial Off
This mode is entered by momentarily depressing the ESP
OFF switch. When in Partial Offmode, the TCS portion
of ESP has been disabled and the ESP/TCS Indicator
Light will be illuminated. All other stability features of
ESP function normally. This mode is intended to be used
if the vehicle is in deep snow, sand, or gravel conditions
and more wheel spin than ESP would normally allow is
110 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

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

rear wheels to rotate at the same speed. This is accom-
plished by simply moving the shift lever to one of these
positions. The 4H and 4L positions are intended for loose,
slippery road surfaces only, and not intended for normal
driving. Driving in the 4H and 4L positions on hard
surfaced roads will cause increased tire wear and damage
to the driveline components.
The 4WD Indicator Light (located in the instrument
cluster) alerts the driver that the vehicle is in four-wheel
drive, and the front and rear driveshafts are locked
together. The light will illuminate when the transfer case
is shifted into the 4H position.
NOTE:Do not attempt to shift when only the front or
rear wheels are spinning. The transfer case is not
equipped with a synchronizer, and the front and rear
driveshaft speeds must be equal for a shift to take place.
Shifting while only the front or rear wheels are spinning
can cause damage to the transfer case. When operating your vehicle in 4L, the engine speed will
be approximately three times (four times for Rubicon
models) that of the 2H or 4H positions at a given road
speed. Take care not to overspeed the engine.
Proper operation of four-wheel drive vehicles depends
on tires of equal size, type, and circumference on each
wheel. Any difference will adversely affect shifting and
cause damage to the transfer case.
Because four-wheel drive provides improved traction,
there is a tendency to exceed safe turning and stopping
speeds. Do not go faster than road conditions permit.
286 STARTING AND OPERATING

N (Neutral) Position
This range disengages the front and rear driveshafts from
the powertrain. To be used for flat towing behind another
vehicle. Refer to “Recreational Towing” in Section 5 of
this manual.
4L Position
This range locks the front and rear driveshafts together,
forcing the front and rear wheels to rotate at the same
speed. This range (4L) provides additional traction and
maximum pulling power for loose, slippery road surfaces
only. Do not exceed 25 mph (40 km/h).
The 4WD Indicator Light (located in the instrument
cluster) will illuminate when the transfer case is shifted
into the 4L position.
Shifting Procedure
2H to 4H or 4H to 2H
Shifting between 2H and 4H can be made with the
vehicle stopped or in motion. If the vehicle is in motion,
shifts can be made up to 50 mph (80 km/h). With the
vehicle in motion, the transfer case will engage/
disengage faster if you momentarily release the accelera-
tor pedal after completing the shift. Apply a constant
force when shifting the transfer case lever.
288 STARTING AND OPERATING

Trac-Lok™ is especially helpful during slippery driving
conditions. With both rear wheels on a slippery surface, a
slight application of the accelerator will supply maxi-
mum traction.