2015 JEEP WRANGLER UNLIMITED Owners Manual

Hill Start Assist (HSA)
The HSA system is designed to assist the driver when
starting a vehicle from a stop on a hill. HSA will maintain
the level of brake pressure the driver applied for a short
period of time after the driver takes their foot off of the
brake pedal. If the driver does not apply the throttle
during this short period of time, the system will release
brake pressure and the vehicle will roll down the hill. The
system will release brake pressure in proportion to
amount of throttle applied as the vehicle starts to move in
the intended direction of travel.

WARNING!
There may be situations on minor hills with a loaded
vehicle, or while pulling a trailer where the system
will not activate and slight rolling may occur, which
could cause a collision with another vehicle or object.
Always remember the driver is responsible for brak-
ing the vehicle.
The system will only work if the intended direction of the
vehicle and vehicle gear match. For example, if the
intended direction is forward up a hill and the vehicle is
in DRIVE (automatic transmission equipped vehicle),
and the activation criteria are met, HSA will activate.
HSA On Automatic Transmission Vehicles
The system will work in REVERSE, and all forward gears
on vehicles equipped with an automatic transmission.
The system will not activate if the vehicle is placed in
NEUTRAL.
HSA On Manual Transmission Vehicles
The system will work in REVERSE, forward gears, and
NEUTRAL on manual transmission equipped vehicles.
The system does not recognize NEUTRAL on manual
vehicles, thus it will hold the vehicle on an incline for a
short period while in NEUTRAL, regardless of clutch
position. If the vehicle is pointed down hill in NEUTRAL
and your foot is not on the clutch, it will roll down hill,
HSA will not hold you in this case. To prevent this, do not
attempt to roll down a hill simply by putting the trans-
mission in NEUTRAL and letting gravity act on the
vehicle. Instead, use the appropriate gear for moving in
the desired direction.
NOTE:
Towing With HSA
HSA will provide assistance when starting on a grade
when pulling a trailer.
472 STARTING AND OPERATING

WARNING!
•If you use a trailer brake controller with your
trailer, your trailer brakes may be activated and
deactivated with the brake switch. If so, when the
brake pedal is released there may not be enough
brake pressure to hold the vehicle and trailer on a
hill and this could cause a collision with another
vehicle or object behind you. In order to avoid
rolling down the hill while resuming acceleration,
manually activate the trailer brake prior to releas-
ing the brake pedal. Always remember the driver is
responsible for braking the vehicle.
• 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.
(Continued)

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:Anytime the ESC system is in the “Full Off”
mode, ERM is disabled. Refer to Electronic Stability
Control (ESC) for a complete explanation of the available
ESC modes.

•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 “ESC Activation/Malfunction Indicator Light” (lo-
cated in the instrument cluster), starts to flash as soon as
the tires lose traction and the ESC system becomes active.
The “ESC Activation/Malfunction Indicator Light” also
flashes when TCS is active. If the “ESC Activation/
Malfunction Indicator Light” begins to flash during ac-
celeration, 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.

WARNING!
•When in ESC Partial Off mode, the TCS function-
ality of ESC, (except for the limited slip feature
described in the TCS section), has been disabled
and the “ESC Off Indicator Light” will be illumi-
nated. When in ESC Partial Off mode, the engine
power reduction feature of TCS is disabled, and
the enhanced vehicle stability offered by the ESC
system is reduced.
• Trailer Sway control (TSC) is disabled when the
ESC system is in the ESC Partial Offmode.
ESC Full Off
This mode is entered by pressing and holding momen-
tarily pressing the ESC OFF switch for five seconds. In the
ESC Full Off mode, the engine torque reduction
and stability features are disabled. Therefore, the en-
hanced vehicle stability offered by ESC is unavailable. In
an emergency evasive maneuver, the ESC system will not
engage to assist in maintaining stability. “ESC Full Off”
mode is intended for off-highway or off-road use only.