CHEVROLET 2010 HHR - Manual (Page 260)

Brake Assist
If this vehicle has ESC with ABS, it also 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 pulsations
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.
Electronic Stability Control (ESC)
The vehicle has an Electronic Stability Control (ESC)
system which combines antilock brake, and traction and
stability control systems that help the driver maintain
directional control of the vehicle in most driving
conditions.
When the vehicle is started and begins to move, the
system performs several diagnostic checks to ensure
there are no problems. The system may be heard or felt
while it is working. This is normal and does not mean
there is a problem with the vehicle. The system
should initialize before the vehicle reaches 20 mph
(32 km/h).
If the system fails to turn on or activate, the ESC/TCS
light comes on, and the ESC OFF and/or SERVICE ESC
message displays.
For more information, see Driver Information Center
(DIC) on page 4-46 and Electronic Stability Control
(ESC)/Traction Control System (TCS) Indicator/Warning
Light on page 4-32.
5-6