2012 Jeep Wrangler Owner Manual - Page 430

428 STARTING AND OPERATING WARNING! With the ESC switched off, the enhanced vehicle stability offered by ESC and ERM are unavailable. In an emergency evasive maneuver, the ESC and ERM systems will not engage to assist in maintaining stability. The "Full Off" ESC mode is intended for off-road use only. 4L Range (4WD Models) ESC Off 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.