From the manual:
• The driver can override the automatic braking function
by pressing the gas pedal, turning ParkSense off via
ParkSense switch, or changing the gear while the automatic
brakes are being applied.
• Automatic brakes will not be available if ESC is not
available.
• Automatic brakes will not be available if there is a
faulted condition detected with the ParkSense Park
Assist system or the Braking System Module.
• The automatic braking function may only be applied if
the vehicle deceleration is not enough to avoid colliding
with a detected obstacle.
• The automatic braking function will not be available if
vehicle is in 4LO transfer case mode.
• The automatic braking function may not be applied fast
enough for obstacles that move toward the rear of the
vehicle from the left and/or right sides.
• The automatic braking function can be enabled/
disabled from the Customer Programmable Features
section of the Uconnect System.
• ParkSense will retain its last known configuration state
for the automatic braking function through ignition
cycles.
• The driver can override the automatic braking function
by pressing the gas pedal, turning the rear system
ParkSense off via the Rear ParkSense switch, or changing
the gear while the automatic brakes are being
applied.
Depending on your model (you don't include your config in your signature) it's in the UConnect settings under Safety/Assistance. Change the "Warning & Braking" to "Warning Only" or "Off".