Straight from the manual;
Partial Off
This mode is entered by momentarily pressing the ESP
OFF switch. When in Partial Off mode, the TCS portion
of ESP has been disabled and the “ESP/TCS Indicator
Light” will be illuminated. All other stability features of
ESP 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 ESP would normally allow is
required to gain traction. To turn ESP on again, momentarily
press the ESP OFF switch. This will restore the
normal “ESP On” mode of operation.
ESP Off (4H Range Only)
This mode is intended for off-highway or off-road use
when ESP stability features could inhibit vehicle maneuverability
due to trail conditions. This mode is entered by
pressing and holding the ESP OFF switch for five seconds
when the vehicle is stopped and the engine is running. In
this mode, all ESP and TCS stability features are turned
off except for the “limited slip” feature described in the
TCS section. After five seconds, a chime will sound, the
“ESP/TCS Indicator Light” will illuminate, and the “ESP
OFF message will appear in the odometer. Refer to
“Compass and Mini-Trip Computer — If Equipped” in
Section 4 of this manual. To turn ESP on again, momentarily
press the ESP OFF switch. This will restore the
normal “ESP On” mode of operation.
NOTE:
• The ESP system will change to “Partial Off” mode if
the vehicle speed exceeds 40 mph (64 km/h). After the
vehicle speed is reduced below 35 mph (56 km/h), the
ESP system will return to “Full Off” mode.
• The “ESP 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.