2007 JEEP GRAND CHEROKEE brake

Driving Up or Down Hills
When going up or down hills, it is possible for your
vehicle to lose or gain speed, even though the Speed
Control is engaged. The automatic transmission may also
downshift to a lower gear, to maintain speed going up or
down hills. If going down a hill steep enough to cause the
vehicle to gain speed, press the brake pedal, which will
disengage the Speed Control and help slow your vehicle.
WARNING!
To help keep your vehicle under control, do not use
Speed Control under these conditions:
²When it is not possible to keep your vehicle at a set
speed.
²On slippery roads, such as on snow or ice.
²In heavy or varying traffic volume, in traffic that varies
in speed, or on winding roads.
²Be sure to turn the Speed Control switch to the OFF
position when not in use to avoid accidental engage-
ment.
130 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

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 systems work
together to enhance vehicle stability and control in vari-
ous driving conditions, and are commonly referred to as
ESP.
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 ªAnti-Lock Brake Systemº in Section 5 of this
manual for more information about ABS.
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 prevail-
ing road conditions. ABS cannot prevent accidents,
including 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.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 131
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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) and engine
power is reduced 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 the
ªESP Partial Offº mode. Refer to ªESP (Electronic Stabil-
ity Program)º in this section.
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.
132 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

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, 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 a BAS-
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.
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.
UNDERSTANDING THE FEATURES OF YOUR VEHICLE 133
3

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 roll overs, 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.
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 applyingthe 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.
²Oversteer - when the vehicle is turning more than
appropriate for the steering wheel position.
²Understeer - when the vehicle is turning less than
appropriate for the steering wheel position.
The9ESP/TCS Indicator Light9located in the instrument
cluster, starts to flash as soon as the tires lose traction and
the ESP system becomes active. The9ESP/TCS Indicator
134 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

WARNING!
²Drivers must be careful when backing up even when
using the Rear Park Assist System. Always check
carefully behind your vehicle, look behind you, and
be sure to check for pedestrians, animals, other
vehicles, obstructions, and blind spots before back-
ing up. You are responsible for safety and must
continue to pay attention to your surroundings. Fail-
ure to do so can result in serious injury or death.
²Before using the Rear Park Assist System, it is
strongly recommended that the ball mount and hitch
ball assembly is disconnected from the vehicle when
the vehicle is not used for towing. Failure to do so
can result in injury or damage to vehicles or ob-
stacles because the hitch ball will be much closer to
the obstacle than the rear fascia when the warning
display turns the red LEDs ON. Also, the sensors
could detect the ball mount and hitch ball assembly,
depending on its size and shape, giving a false
indication that an obstacle is behind the vehicle.
NOTE:Clean all four Rear Park Assist Sensors regularly,
taking care not to scratch or damage them. The sensors
must not be covered with ice, snow, slush, mud, dirt or
debris. Failure to do so can result in the system not
working properly. The system might not detect an ob-
stacle behind the fascia or it could provide a false
indication that an obstacle is behind the fascia.
Assure objects are not within 11.8 inches (30 cm) from the
rear fascia while driving the vehicle. Failure to do so can
result in the system misinterpreting a close object as a
sensor problem, causing the9SERVICE PARK ASSIST
SYSTEM9message to be displayed in the instrument
cluster.
Ultrasonic noise from airbrakes of nearby trucks, air
powered jackhammers and air powered shop tools, to
name a few, will cause the Rear Park Assist System to be
disabled until the ultrasonic noise is no longer present.
142 UNDERSTANDING THE FEATURES OF YOUR VEHICLE

INSTRUMENT CLUSTER DESCRIPTION
1. Speedometer
Indicates vehicle speed.
2. Brake Warning Light
The BRAKE warning light will come on when
the ignition is first turned on, and stay on
briefly as a bulb check. If the bulb does not
come on during starting, have the bulb re-
paired promptly. If the light stays on longer, it may be an
indication that the parking brake has not been released.
If the light remains on when the parking brake is off, it
indicates a possible brake hydraulic system malfunction
or low fluid level. In this case, the BRAKE warning light
will remain on until the cause is corrected. If a brake
malfunction is indicated, immediate repair is necessary
and continued operation of the vehicle in this condition is
dangerous.3. Turn Signal Indicator Light
The arrow will flash with the exterior turn signal
when the turn signal lever is operated.
If the vehicle electronics sense that the vehicle has
traveled about one mile with the turn signals on, a chime
will sound to alert you to turn the signals off. If either
indicator flashes at a rapid rate, check for a defective
outside light bulb.
4. High Beam Indicator Light
Indicates that headlights are on high beam.
5. Malfunction Indicator Light
This light is part of an onboard diagnostic system
called OBD II that monitors engine and auto-
matic transmission control systems. The light will
illuminate when the key is in the ON position before
172 UNDERSTANDING YOUR INSTRUMENT PANEL

engine start. If the bulb does not come on when turning
the key from OFF to ON, have the condition checked
promptly.
Certain conditions such as a loose or missing gas cap,
poor fuel quality, etc. may illuminate the light after
engine start. The vehicle should be serviced if the light
stays on through several of your typical driving cycles. In
most situations the vehicle will drive normally and will
not require towing.
The Malfunction Indicator Light flashes to alert you to
serious conditions that could lead to immediate loss of
power or severe catalytic converter damage. The vehicle
should be serviced as soon as possible if this occurs.
6. Airbag Warning Light
This light turns on and remains on for 6 to 8
seconds as a bulb check when the ignition
switch is first turned ON. If the light is not onduring starting, stays on, or turns on while driving, have
the system inspected by an authorized dealer as soon as
possible.
7. Anti-Lock Brake Warning Light
This light monitors the Anti-Lock Brake System.
The light will turn on when the ignition switch is
turned to the ON position and may stay on for as long as
four seconds.
If the ABS light remains on or turns on while driving, it
indicates that the Anti-Lock portion of the brake system
is not functioning and that service is required. However,
the conventional brake system will continue to operate
normally if the BRAKE warning light is not on.
If the ABS light is on, the brake system should be serviced
as soon as possible to restore the benefits of Anti-Lock
brakes. If the ABS light does not turn on when the
Ignition switch is turned to the ON position, have the
light inspected by an authorized dealer.
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