Jeep Wrangler Owner's Manual page 156

HDC has three states:
1. Off (feature is not enabled and will not activate).
2. Enabled (feature is enabled and ready but activation
conditions are not met, or driver is actively overriding
with brake or throttle application).
3. 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:
 The driveline is in 4WD Low.
 The vehicle speed is below 5 mph (8 km/h).
 The parking brake is released.
 The driver door is closed (If doors are attached, then
the 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 acti-
vate
 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)
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 trans-
mission 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:
 The driver overrides HDC set speed with throttle or
brake application.
 The vehicle speed exceeds 20 mph (32 km/h) but
remains below 40 mph (64 km/h).
 The vehicle is on a downhill grade of insufficient magni-
tude, is on level ground, or is on an uphill grade.
 The 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.
SAFETY 155