9 BW8207 Bendix Global Scalable Brake Control (GSBC) System Operator’s Manual
BENDIX GSBC SYSTEM OPERATION
Bendix® GSBC® will be controlled and operated in a similar manner to previous Bendix
brake control systems. The driver will always be in control of the service brakes, which
will be operated by the brake pedal under the driver’s foot.
Experienced drivers may notice more solenoid noises during service brake operation.
This is normal and is an audible conrmation that the system is operating as expected.
GSBC can operate in two modes: Electronic Primary Mode and Pneumatic Backup
Mode. In Electronic Primary Mode, the driver’s movement of the brake pedal is
translated into an electronic request for air that is interpreted by the central Brake
Control ECU (Electronic Control Unit) and sent to the Electro-Pneumatic Modules
(EPMs) that have taken the place of the traditional relay valve. This electronic
control allows the system to deliver the precise pressure required to each controlled
foundation brake to ensure the desired brake response and provide improved brake
balance and feel across dierent load conditions.
NOTE: In the event of a serious system malfunction, the GSBC ECU may be unable
to maintain electronic control of the system. In the event of this unlikely occurrence,
the system will revert to Pneumatic Backup Mode.
In Pneumatic Backup Mode, the system will rely on the pneumatic pressure sent
by the foot brake module to the EPMs. This will ensure that the vehicle has all of the
designed braking power available to bring the vehicle to a safe stop.
When the system is operating in this mode:
• A red warning lamp will appear on the dashboard accompanied by “a Truck
brake failure” message.
• All of the electronic driver safety features (ABS, Stability Control, Traction
Control, and so on) may be unavailable.
• The system will be unable to prevent wheel end lockup, or provide stability
assistance.
• Brake pedal feel and response will likely be different as compared to
operation in Electronic Primary Mode.
As a result of these changes and limitations, drivers must immediately bring
the vehicle to a safe stop if the red warning lamp appears on the dashboard
and stays illuminated. The vehicle must be serviced as soon as possible by
a qualied service facility, and the issue(s) that caused the system to enter
Pneumatic Backup Mode should be identied, addressed, and corrected.
Only after a repair has been completed, and the fault is veried to be cleared, can
the vehicle be returned to service.
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