freightliner S2 Operator's Manual page 76

Transmission
WARNING
When going downhill, use a combination of
downshifting, braking, and other retarding de-
vices to control vehicle speed and the engine's
rated governed speed. Failure to do so could re-
duce vehicle braking, possibly causing loss of
vehicle control and resulting in personal injury or
property damage.
When going downhill, downshift to a lower transmis-
sion range to increase engine braking and to help
maintain control. The transmission has a feature to
prevent automatic upshifting above the lower range
selected. However, during downhill operation, if the
engine governed speed is exceeded in the lower
range, the transmission may upshift to the next
higher range.
1 (First Range)
Use the first range when pulling through mud or
deep snow, when maneuvering in tight spaces, or
when driving up or down steep grades. First range
provides the vehicle with its maximum driving torque
and maximum engine braking effect. Push the down
arrow until the first range appears on the display.
Up and Down Arrows
When a lower range is desired, after D has been
pressed, press the down arrow until the desired
range is shown on the display. Pressing the down
arrow continuously causes the range position to con-
tinue to go down until the button is released or the
lowest range is attained.
When the transmission is in drive and the down
arrow has the transmission in a lower range position,
press the up arrow to shift to a higher selector posi-
tion. Continuously pressing the up arrow causes the
range position to continue to rise until the button is
released or the highest available position is attained.
Continuously pressing the up or down arrows does
not override the transmission automatic shifting op-
eration. If a higher or lower position is selected, the
transmission continues shifting through the ranges
according to the vehicle operating characteristics
until the highest or lowest selection position is
reached.
10.5
Mode Button
The MODE button starts a specialized input or output
function that has been previously programmed into
the ECU or TCM. Pressing the MODE button
changes transmission operation for a specific func-
tion.
Mode Indicator LED
When the MODE button is pressed, the mode indica-
tor LED illuminates. A mode identification label, lo-
cated above the MODE button, identifies the function
associated with a mode change.
Digital Display
The dual digital display shows both the selected
range (SELECT) and actual range attained (MONI-
TOR). The single digital display shows the selected
range.
Oil Level Sensor
Allison 3000 Series transmissions have an electronic
oil level sensor to read fluid level information. The
fluid level diagnostic will display whether the oil level
is OK, too low, or too high. It will also display a de-
fault code and indicate if the preconditions (of receiv-
ing the fluid level information) are not met.
IMPORTANT: Maintain the proper fluid level at
all times. If the fluid level is too low, the con-
verter and clutch do not receive an adequate
supply of fluid. If the level is too high, the trans-
mission may shift erratically or overheat.
To access the oil level display mode, park the vehicle
on a level surface, shift to N (neutral), apply the
parking brake, and idle the engine. Then simultane-
ously press both the up and down arrows once. The
oil level will display at the end of a two-minute count-
down.
Diagnostic Codes
Diagnostic codes are numerical indications relating to
a malfunction in transmission operation. These codes
are logged in the TCM/ECU memory. The most se-
vere or most recent code is listed first. A maximum of
five codes (numbered d1-d5) may be listed in
memory at one time. If the mode indicator LED is
illuminated, the displayed code is active. If it is not
illuminated, the displayed code is not active.