From the 2012 Wrangler Owners' Manual (underlined emphasis is mine):
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) 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 ESC are in either the “Partial Off” or “Full Off”
modes. 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. The
system detects an emergency braking situation by sensing
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 braking
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
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 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 maneuvers.
Electronic Roll Mitigation (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.
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
Electronic Stability Control (ESC)
This system enhances directional control and stability of
the vehicle under various driving conditions. The ESC
corrects for over/under steering of the vehicle by applying
the brake of the appropriate wheel to assist in
counteracting the over/under steer condition. Engine
power may also be reduced to help the vehicle maintain
the desired path.
ESC 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, ESC applies the brake of the appropriate
wheel to assist in counteracting the oversteer or
• 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” (located
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 acceleration, 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.
The ESC system has two available operating modes in
4H range. The system has one operating mode in 4L
range. Two-wheel drive vehicles and four-wheel drive
vehicles in 2H range have two operating modes.
4H Range (4WD Models) Or 2WD Models
This is the normal operating mode for ESC in 4H and
This mode is entered by momentarily pressing the ESC
OFF switch. When in Partial Off mode, the TCS portion of
ESC has been disabled and the “ESC Activation/Malfunction
Indicator Light” will be illuminated.
All other stability features of ESC function normally. This
mode is intended to be used if the vehicle is in deep
snow, sand, or gravel conditions and more wheel spin
than ESC would normally allow is required to gain
traction. To turn ESC on again, momentarily press the
ESC OFF switch. This will restore the normal “ESC On”
mode of operation.
4L Range (4WD Models)
This is the normal operating mode for ESC in 4L range.
Whenever the vehicle is started in 4L range, or the
transfer case (if equipped) is shifted from 4H range or
NEUTRAL to 4L range, the ESC system will be in this
mode. In 4L range, ESC and TCS, except for the “limited
slip” feature described in the TCS section, are turned off
until the vehicle reaches a speed of 40 mph (64 km/h). At
40 mph (64 km/h), the normal ESC stability function
returns but TCS remains off. When the vehicle speed
drops below 35 mph (56 km/h), the ESC system shuts off.
The ESC is off at low vehicle speeds in 4L range so that it
will not interfere with off-road driving, but the ESC
function returns to provide the stability feature at speeds
above 40 mph (64 km/h). The “ESC Activation/
Malfunction Indicator Light” will always be illuminated
in 4L range when ESC is off.
NOTE: The “ESC OFF” message will display and the
audible chime will sound when the shift lever is placed in
the PARK position from any position other than PARK,
and then moved out of the PARK position. This will
occur even if the message was previously cleared.
For the record, I'm probably judging you for your bad grammar or spelling.