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 condi-
tions will make it desirable to restrict automatic shift-
ing 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 digi-
tal 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 (en-
gine governed speed) is reduced.
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. 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 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 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 de-
fault code and indicate if the preconditions (of receiv-
ing the fluid level information) are not met.
IMPORTANT: Maintain the 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
Drivetrain
8.7
