Mercedes-Benz TRAVEGO, Operating Instructions Manual

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Transmission shift systems
Transmission shift system GO 250-8 (system description)
Transmission shift system GO 250-8
(system description)
The GO 250-8 transmission is adapted
to the engine by a dry clutch. As the
clutch is controlled automatically by the
transmission system, there is no need
for a clutch pedal.
Gears are shifted and the clutch is op-
erated electropneumatically. An elec-
tronics unit attached to the transmission
controls the valves of the pneumatic ac-
tuating cylinders at the gear, gate and
clutch.
The driver selects the direction of travel
using the selector lever on the steer-
ing column and is then able to influence
the speed of the vehicle using only the
accelerator pedal and brake pedal. Ad-
vantage: The driver is relieved of having
to change gear and use a clutch.
Using the selector lever on the steering
column, the driver can choose between
automatic and manual gear selection.
Manual gear selection should, however,
only be used in special cases, e.g. to
brake the bus or when driving over
mountainous terrain. Automatic mode
should be used for all normal driving
conditions. In automatic mode, 2 shift
programs are available: “Basic” and
“Dynamic”. The “Basic” shift program is
optimised for fuel economy and should
generally be the program of choice. In
the “Dynamic” shift program, upshifts
take place at higher engine speeds.
Although this offers faster acceleration, it
also results in higher fuel consumption.
As the basis for selecting the appropri-
ate gear, the intelligent gear selection
function in automatic mode takes into
consideration the driver's commands (op-
eration of the accelerator pedal and ser-
vice brake), the current engine operating
state, uphill or downhill gradients and
the load on the bus. This achieves the
optimum compromise between comfort,
fuel economy and wear.
The drive control module coordinates the
functions of the drivetrain by informing
the engine control module how much en-
gine torque is required and by informing
the transmission control module of the gear to be selected and the clutch posi-
tion to be adopted.
The mechatronic transmission and en-
gine control units then implement the
control commands of the drive control
for the engine and transmission.
The screen in the instrument panel
shows all necessary system information
(e.g. gear, malfunction, etc.) to the
driver.
The system has a failsafe mode that can
be activated in the event of a fault in the
transmission shift system. In this mode,
it is possible to drive the bus away from
areas of danger or to the nearest work-
shop. Even if no faults are present, it
is possible to activate failsafe mode for
training purposes as preparation for this
situation.
Refer to “Operation of GO 250-8
failsafe mode” in this section.
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TRAVEGO / TRAVEGO M / TRAVEGO L (Euro VI)/07.2014 GB