Electronic Parking Brake Control Module Description
Vehicles with the electric parking brake have a switch in the
center console, which takes the place of the manual parking brake
system, the foot pedal and release handle. In case of insufficient
electrical power, the electric parking brake cannot be applied or
released.
Electric Parking Brake Control Module
The electric parking brake module has an internal motor, apply
actuator, release actuator, and temperature sensor. The electric
parking brake module also contains the logic for applying and
releasing the parking brake when commanded by the parking brake
switch. When the electric parking brake module receives a signal
from the switch, the internal circuit board temperature is checked
to verify it is within operating range before the module performs
the requested operation.
The electric parking brake module receives hard wired signals
from the apply/release switch and communication enable. The
electric parking brake module receives wheel speed sensor signals,
engine torque, gear information, brake pedal signal, and etc.
through GM-LAN.
Electric Parking Brake Apply
The electric parking brake can be applied any time the vehicle
is stopped or in motion. The electric parking brake is applied by
momentarily lifting up on the electric parking brake switch. Once
fully applied, the BRAKE light will turn on, and the DIC message
"Park Brake Set" will be displayed. If the electric parking brake
is applied while the vehicle is in motion, a chime will sound, and
the DIC message "Release Park Brake Switch" will be displayed.
If the BRAKE light is on, either the electric parking brake is
applied, or there is a malfunction in the hydraulic brake
system.
If the BRAKE light is flashing, the electric parking brake is
only partially applied or released, or there is a problem with the
electric parking brake. The DIC message "Service Park Brake" will
be displayed.
Electric Parking Brake Release
To release the electric parking brake, turn the ignition switch
to the ON or RUN position, apply and hold the brake pedal, and push
down momentarily on the electric parking brake switch. When the
electric parking brake is released the BRAKE light turns off and
the DIC message "Park Brake Released" is displayed.
The electric parking brake will automatically release if the
vehicle is running and put in motion.
The electric parking brake can be used to prevent roll back for
vehicles with a manual transmission taking off on a hill. In a
situation where no roll back is desired, an applied electric
parking brake will allow both feet to be used for the clutch and
accelerator pedals in preparation for starting the vehicle moving
in the intended direction. In this situation, perform the normal
clutch and accelerator actions required to begin moving the
vehicle. There is no need to push the switch to release the
electric parking brake. To disable this feature lift and hold the
electric parking brake switch while the vehicle is in motion, this
will keep the electric parking brake applied.
Electric Parking Brake Cable Tension Release
If the park brake cable tension cannot be released under normal
mode of operation, it can be released manually. The manual release
capability will make it possible for the driver to transfer the
vehicle into a movable state in the case of a failure of the
electric parking brake system. The procedure can be found in the
Repair Instructions, Parking Brake Cable Adjuster Disabling.
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