2008 JEEP WRANGLER Owners Manual

Tapping RESUME ACCEL once will result in a 1 mph (1.6
km/h) speed increase. Each time the lever is tapped,
speed increases so that tapping the lever three times will
increase speed by 3 mph (4.8 km/h), etc.
To decrease speed while speed control is ON, push down
and hold SET DECEL. Release the lever when the desired
speed is reached, and the new speed will be set.
Tapping the SET DECEL button once will result in a 1
mph (1.6 km/h) speed decrease. Each time the button is
tapped, speed decreases.
NOTE:The Electronic Speed Control System has been
designed to shut down if multiple speed control switch
functions are operated simultaneously in order to ensure
proper operation. If this occurs, the system can be
reactivated by pushing the speed control switch ON/
OFF button and re-setting the desired vehicle SET speed.Manual Transmission
Depressing the clutch pedal will disengage the speed
control. A slight increase in engine RPM before the speed
control disengages is normal.
Vehicles equipped with manual transmissions may need
to be shifted into a lower gear to climb hills without
speed loss.
WARNING!
Speed Control can be dangerous where the system
can’t maintain a constant speed. Your vehicle could
go too fast for the conditions, and you could lose
control. An accident could be the result. Do not use
Speed Control in heavy traffic or on roads that are
winding, icy, snow-covered, or slippery.
104 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

To Accelerate For Passing
Depress the accelerator as you would normally. When the
pedal is released, the vehicle will return to the set speed.
Using Speed Control On Hills
NOTE:The speed control system maintains speed up
and down hills. A slight speed change on moderate hills
is normal.
On steep hills, a greater speed loss or gain and/or more
frequent downshifts (auto transmission only) may occur
so it may be preferable to drive without speed control.
ELECTRONIC BRAKE CONTROL SYSTEM
Your vehicle is equipped with an advanced electronic
brake control system that includes ABS (Anti-Lock Brake
System), TCS (Traction Control System), BAS (Brake
Assist System), ERM (Electronic Roll Mitigation), and ESP (Electronic Stability Program). All five of these
systems work together to enhance vehicle stability and
control in various driving conditions.
ABS (Anti-Lock Brake System)
This system aids the driver in maintaining vehicle control
under adverse braking conditions. The system controls
hydraulic brake pressure to prevent wheel lock-up and
help avoid skidding on slippery surfaces during braking.
Refer to “Anti-Lock Brake System” in Section 5 of this
manual for more information about ABS.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 105
3

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

BAS (Brake Assist System)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. The
system detects an emergency braking situation by sens-
ing the rate and amount of brake application and then
applies optimum pressure to the brakes. This can help
reduce braking distances. The BAS complements the
anti-lock brake system (ABS). Applying the brakes very
quickly results in the best BAS assistance. To receive the
benefit of the system, you must apply continuous brak-
ing pressure during the stopping sequence. Do not
reduce brake pedal pressure unless braking is no longer
desired. Once the brake pedal is released, the BAS is
deactivated.WARNING!
BAS (Brake Assist System) cannot prevent the natu-
ral laws of physics from acting on the vehicle, nor can
it increase the traction afforded by prevailing road
conditions. BAS cannot prevent accidents, including
those resulting from excessive speed in turns, driving
on very slippery surfaces, or hydroplaning. Only a
safe, attentive, and skillful driver can prevent acci-
dents. The capabilities of a BAS-equipped vehicle
must never be exploited in a reckless or dangerous
manner which could jeopardize the user’s safety or
the safety of others.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 107
3

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!
Many factors, such as vehicle loading, road condi-
tions and driving conditions, influence the chance
that wheel lift or rollover may occur. ERM cannot
prevent all wheel lift or rollovers, especially those
that involve leaving the roadway or striking objects
or other vehicles. Only a safe, attentive, and skillful
driver can prevent accidents. The capabilities of an
ERM-equipped vehicle must never be exploited in a
reckless or dangerous manner which could jeopar-
dize the user’s safety or the safety of others.
108 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

ESP (Electronic Stability Program)
This system enhances directional control and stability of
the vehicle under various driving conditions. ESP cor-
rects for over/under steering of the vehicle by applying
the brake of the appropriate wheel to assist in counter-
acting the over/under steer condition. Engine power
may also be reduced to help the vehicle maintain the
desired path.
ESP uses sensors in the vehicle to determine the vehicle
path intended by the driver and compares it to the actual
path of the vehicle. When the actual path does not match
the intended path, ESP applies the brake of the appropri-
ate wheel to assist in counteracting the oversteer or
understeer condition.
•Oversteer - when the vehicle is turning more than
appropriate for the steering wheel position.
•Understeer - when the vehicle is turning less than
appropriate for the steering wheel position.
The ESP/TCS Indicator Light (located in the instrument
cluster), starts to flash as soon as the tires lose traction
and the ESP system becomes active. The ESP/TCS Indi-
cator Light also flashes when TCS is active. If the
ESP/TCS Indicator Light begins to flash during accelera-
tion, ease up on the accelerator and apply as little throttle
as possible. Be sure to adapt your speed and driving to
the prevailing road conditions.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 109
3

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

required to gain traction. To turn ESP on again, momen-
tarily depress the ESP OFF switch. This will restore the
normal “ESP On” mode of operation.
NOTE:To improve the vehicle’s traction when driving
with snow chains, or starting off in deep snow, sand, or
gravel, it may be desirable to switch to the “Partial Off” mode by pressing the ESP OFF switch. Once the situation
requiring ESP to be switched to the “Partial Off” mode is
overcome, turn ESP back on by momentarily depressing
the ESP OFF switch. This may be done while the vehicle
is in motion.
ESP Off (4H Range Only)
This mode is intended for off-highway or off-road use
when ESP stability features could inhibit vehicle maneu-
verability due to trail conditions. This mode is entered by
depressing and holding the ESP OFF switch for five
seconds when the vehicle is stopped and the engine is
running. In this mode, all ESP and TCS stability features
are turned off except for the “limited slip” feature de-
scribed in the TCS section. After five seconds, a chime
will sound, the ESP/TCS Indicator Light will illuminate,
and the “ESP OFF
message will appear in the odometer.
Refer to “Compass and Mini-Trip Computer — If
Equipped” in Section 4 of this manual. To turn ESP on
ESP OFF Switch
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 111
3