GMC 2012 Canyon Owner's Manual page 223

To release the parking brake,
hold the regular brake pedal down.
Pull the bottom edge of the lever,
located above the parking brake
pedal, with the parking brake
symbol, directly rearward to
release the parking brake.
If the ignition is on when the parking
brake is released, the brake system
warning light will go off.
If you are towing a trailer and are
parking on any hill, see
.
This vehicle has a brake assist
feature designed to assist the driver
in stopping or decreasing vehicle
speed in emergency driving
conditions. This feature uses the
stability system hydraulic brake
control module to supplement the
power brake system under
conditions where the driver has
quickly and forcefully applied the
brake pedal in an attempt to quickly
stop or slow down the vehicle.
The stability system hydraulic brake
control module increases brake
pressure at each corner of the
vehicle until the ABS activates.
Minor brake pedal pulsation or
pedal movement during this time is
normal and the driver should
continue to apply the brake pedal
as the driving situation dictates.
The brake assist feature will
automatically disengage when the
brake pedal is released or brake
pedal pressure is quickly
decreased.