Jeep Wrangler: Electronic Stability Control (ESC) / Hill Descent Control (HDC) — If Equipped
HDC is intended for low speed off-road driving
while in 4WD Low. HDC maintains vehicle speed
while descending hills during various driving
situations. HDC controls vehicle speed by
actively controlling the brakes.
HDC has three states:
- Off (feature is not enabled and will not
activate).
- Enabled (feature is enabled and ready but
activation conditions are not met, or driver
is actively overriding with brake or throttle
application).
- Active (feature is enabled and actively
controlling vehicle speed).
Enabling HDC
HDC is enabled by pushing the HDC switch, but
the following conditions must also be met to
enable HDC:
- Driveline is in 4WD Low.
- Vehicle speed is below 5 mph (8 km/h).
- The parking brake is released.
- The driver door is closed. (If doors are
attached, then door must be closed. If doors
are detached, then driver seat belt must be
buckled.)
Activating HDC
Once HDC is enabled it will activate
automatically if driven down a grade of
sufficient magnitude. The set speed for HDC is
selectable by the driver, and can be adjusted by
using the gear shift +/-. The following
summarizes the HDC set speeds:
HDC Target Set Speeds
- P = No set speed. HDC may be enabled but
will not activate
- R = 0.6 mph (1 km/h)
- N = 1.2 mph (2 km/h)
- D = 0.6 mph (1 km/h)
- 1st = 0.6 mph (1 km/h)
- 2nd = 1.2 mph (2 km/h)
- 3rd = 1.8 mph (3 km/h)
- 4th = 2.5 mph (4 km/h)
- 5th = 3.1 mph (5 km/h)
- 6th = 3.7 mph (6 km/h)
- 7th = 4.3 mph (7 km/h)
- 8th = 5.0 mph (8 km/h)
- 9th = 5.6 mph (9 km/h) – If Equipped
NOTE:
During HDC the +/- shifter input is used for HDC
target speed selection, but will not affect the
gear chosen by the transmission. When actively
controlling HDC the transmission will shift
appropriately for the driver-selected set speed
and corresponding driving conditions.
Driver Override
The driver may override HDC activation with
throttle or brake application at any time.
Deactivating HDC
HDC will be deactivated but remain available if
any of the following conditions occur:
- Driver overrides HDC set speed with throttle
or brake application.
- Vehicle speed exceeds 20 mph (32 km/h)
but remains below 40 mph (64 km/h).
- Vehicle is on a downhill grade of insufficient
magnitude, is on level ground, or is on an
uphill grade.
- Vehicle is shifted to PARK.
Disabling HDC
HDC will be deactivated and disabled if any of
the following conditions occur:
- The driver pushes the HDC switch.
- The driveline is shifted out of 4WD Low.
- The parking brake is applied.
- The driver door opens. (Driver door opens if
doors are attached or driver seat belt is
unbuckled if doors are detached.)
- The vehicle is driven greater than 20 mph
(32 km/h) for greater than 70 seconds.
- The vehicle is driven greater than 40 mph
(64 km/h) (HDC exits immediately).
- HDC detects excessive brake temperature.
Feedback To The Driver
The instrument cluster has an HDC icon and the
HDC switch has an indicator light, which offers
feedback to the driver about the state HDC is in.
- The cluster icon and switch indicator light will
illuminate and remain on solid when HDC is
enabled or activated. This is the normal operating
condition for HDC.
- The cluster icon and switch indicator light will
flash for several seconds then extinguish
when the driver pushes the HDC switch but
enable conditions are not met.
- The cluster icon and switch indicator light will
flash for several seconds then extinguish
when HDC disables due to excess speed.
- The cluster icon and switch indicator light will
flash when HDC deactivates due to overheated
brakes. The flashing will stop and
HDC will activate again once the brakes have
cooled sufficiently.
WARNING!
HDC is only intended to assist the driver in
controlling vehicle speed when descending
hills. The driver must remain attentive to the
driving conditions and is responsible for
maintaining a safe vehicle speed.
The ESC Activation/Malfunction
Indicator Light in the instrument
cluster will come on when the ignition
is turned to the “ESC On” mode. It
should go out with the engine running...
The HSA system is designed to mitigate roll
back 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...
Other information:
While in a forward gear, the engine will start
when the brake pedal is released or the throttle
pedal is pressed. The transmission will
automatically re-engage upon engine restart.
Conditions That Will Cause The Engine To Start
Automatically While In Autostop Mode:
The transmission selector is moved out of
DRIVE...
When off-road driving, shift into 4WD Low for
additional traction and control on slippery or
difficult terrain, ascending or descending steep
hills, and to increase low speed pulling power.
This range should be limited to extreme
situations such as deep snow, mud, steep
inclines, or sand where additional low speed
pulling power is needed...