freightliner M2 Plus 2023 Manual page 185

transmission will upshift automatically through each
range. As the vehicle slows, the transmission will
downshift automatically.
NOTICE
Do not idle in drive for more than 5 minutes.
Extended idling in drive may cause transmission
overheating and damage. Always select neutral if
time at idle is longer than 5 minutes.
NOTE: The shift into drive may not succeed if a
range inhibitor is active. When drive is selected,
always be sure that D is not flashing.
5, 4, 3, and 2 (Fifth, Fourth, Third, and
Second Ranges)
Occasionally, road conditions, load, or traffic
conditions will make it desirable to restrict automatic
shifting to a lower range. Lower ranges provide
greater braking for going down grades. The lower the
range, the greater the braking effect.
Push the up or down arrows on the push-button shift
selector to select individual forward ranges. The
digital display will display your choice of range. When
a lower range is selected, the transmission may not
downshift until the vehicle speed or engine RPM
(engine governed speed) is reduced.
WARNING
When going downhill, use a combination of
downshifting, braking, and other retarding
devices to control vehicle speed and the engine's
rated governed speed. Failure to do so could
reduce vehicle braking, possibly causing loss of
vehicle control and resulting in personal injury or
property damage.
When going downhill, downshift to a lower
transmission 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
Automated and Automatic Transmissions
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
continue 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
position. Pressing the up arrow continuously causes
the range position to continue to rise until the button
is released or the highest available position is
attained.
Pressing the up or down arrows does not override
the transmission automatic shifting operation. 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 selected position is reached.
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
function.
Mode Indicator LED
When the MODE button is pressed, the mode
indicator LED illuminates. A mode identification label,
located 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
(MONITOR). The single digital display shows the
selected range.
Oil Level Sensor
Allison MD 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
default code and indicate if the preconditions (of
receiving the fluid level information) are not met.
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