brake JEEP CHEROKEE TRAILHAWK 2015 Owner's Manual

ELECTRONIC BRAKE CONTROL SYSTEM
Your vehicle is equipped with an advanced electronic
brake control system commonly referred to as ESC. This
system includes Anti-Lock Brake System (ABS), Traction
Control System (TCS), Brake Assist System (BAS), Hill
Start Assist (HSA), Electronic Roll Mitigation (ERM), and
Electronic Stability Control (ESC). These systems work
together to enhance both vehicle stability and control in
various driving conditions.
Your vehicle is also equipped with Trailer Sway Control
(TSC), Ready Alert Braking (RAB) and Rain Brake Sup-
port (RBS). Further, all vehicles equipped with a two-
speed power transfer unit have Hill Descent Control
(HDC) and some vehicles may also be equipped with
Selec Speed Control (SSC).
Anti-Lock Brake System (ABS)
The Anti-Lock Brake System (ABS) is designed to aid the
driver in maintaining vehicle control under adverse
braking conditions. The system operates with a separate
computer to modulate hydraulic pressure, to prevent
wheel lock-up and help avoid skidding on slippery
surfaces.
All vehicle wheels and tires must be the same size and
type, and tires must be properly inflated, to produce
accurate signals for the computer.

The ABS conducts a low-speed self-test at about 12 mph
(20 km/h). If you have your foot lightly on the brake
while this test is occurring, you may feel slight pedal
movement. The movement can be more apparent on ice
and snow. This is normal.
The ABS pump motor runs during the self-test at 12 mph
(20 km/h) and during an ABS stop. The pump motor
makes a low humming noise during operation, which is
normal.

Traction Control System (TCS)
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, Brake Limited
Differential (BLD), 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 ESC are in the “Partial Off” mode
or the “Full Off” mode. Refer to “Electronic Stability
Control (ESC)” in this section for further information.
Brake Assist System (BAS)
The BAS is designed to optimize the vehicle’s braking
capability during emergency braking maneuvers. Thesystem 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
“pump” the brakes). Do not reduce brake pedal pressure
unless braking is no longer desired. Once the brake pedal
is released, the BAS is deactivated.

WARNING!(Continued)
road conditions. BAS cannot prevent collisions, in-
cluding those resulting from excessive speed in
turns, driving on very slippery surfaces, or hydro-
planing. 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.
Electronic Roll Mitigation (ERM)
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 vehicle’s speed
are sufficient to potentially cause wheel lift, it then
applies the appropriate brake and may also reduce
engine power to lessen the chance that wheel lift will
occur. ERM will only intervene during very severe or evasive driving maneuvers. 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 road-
way, or striking objects or other vehicles.
NOTE:
ERM is disabled anytime the ESC is in “Full Off”
mode. Refer to Electronic Stability Control (ESC) for a
complete explanation of the available ESC modes.

WARNING!(Continued)
be exploited in a reckless or dangerous manner,
which could jeopardize the user’s safety or the safety
of others.
Hill Start Assist (HSA)
The HSA system is designed to help the driver accelerate
the vehicle from a complete stop while on an incline. If
the driver releases the brake while stopped on an incline,
HSA will continue to hold the brake pressure for a short
period. If the driver does not apply the throttle before this
time expires, the system will release brake pressure and
the vehicle will roll down the hill as normal. The system
will release brake pressure in proportion to amount of
throttle applied. The following conditions must be met in order for HSA to
activate:
•
The vehicle must be stopped.
• The vehicle must be on a 7% (approximate) grade or
greater hill.
• The gear selection must match vehicle uphill direction
(i.e., vehicle facing uphill is in forward gear; vehicle
backing uphill is in REVERSE gear).
• For vehicles equipped with an automatic transmission,
the HSA will work in REVERSE gear and all forward
gears. The system will not activate if the transmission
is in PARK.
506 STARTING AND OPERATING

WARNING!
There may be situations where the Hill Start Assist
(HSA) will not activate and slight rolling may occur,
such as on minor hills or with a loaded vehicle, or
while pulling a trailer. HSA is not a substitute for
active driving involvement. It is always the driver ’s
responsibility to be attentive to distance to other
vehicles, people, and objects, and most importantly
brake operation to ensure safe operation of the ve-
hicle under all road conditions. Your complete atten-
tion is always required while driving to maintain
safe control of your vehicle. Failure to follow these
warnings can result in a collision or serious personal
injury.
Towing With HSA
HSA will provide assistance during acceleration on an
incline while towing a trailer.

WARNING!(Continued)
•HSA is not a parking brake. Always apply the
parking brake fully when leaving your vehicle.
Also, be certain to leave the transmission in PARK.
• Failure to follow these warnings can result in a
collision or serious personal injury.
Disabling And Enabling HSA
If you wish to turn off the HSA system, it can be done
using the Uconnect® Access Settings. Refer to
“Uconnect® Access Settings” in “Understanding Your
Instrument Panel” for further information.
Hill Descent Control (HDC) — If Equipped

•The cluster icon and switch lamp will flash when HDC
deactivates due to overheated brakes. The flashing will
stop and HDC will activate again once the brakes have
cooled sufficiently.
The Hill Descent Switch is located within the Selec-
Terrain knob in the upper right position.

•The cluster icon and switch lamp will flash for several
seconds then extinguish when the driver presses the
SSC switch but enable conditions are not met.
• The cluster icon and switch lamp will flash for several
seconds then extinguish when SSC deactivates due to
excess speed.
• The cluster icon and switch lamp will flash then
extinguish when SSC deactivates due to overheated
brakes.

Light” will flash, the engine power may be reduced and
you may feel the brakes being applied to individual
wheels to attempt to stop the trailer from swaying. TSC is
only active in the default “ESC On” mode. TSC can be
disabled by pressing the “ESC Off” switch and entering
“ESC Partial Off” mode. It is not active in the “ESC
Partial Off” or “ESC Full Off” modes. Refer to the ESC
portion of this section for an explanation of the different
ESC operating modes.
NOTE:TSC cannot stop all trailers from swaying.