Allison Automatic Transmissions - freightliner M2 Plus 2023 Manual

Automated and Automatic Transmissions
relearn these inputs for the first few shifts to make
the proper adjustments.
Coasting
When coasting to a stop on level terrain, the
transmission system may not downshift into the lower
gears. It will select a gear after the throttle is applied.
Transmission Low Air Warning
CAUTION
If the yellow "Caution: Transmission Air Supply
Low" popup appears while the vehicle is in
operation, slow down, safely pull the vehicle off
the road, then correct the problem.
Pneumatic controls are used to shift the
transmission. If there is inadequate air pressure, a
yellow caution pop-up will appear and the quality of
gear shifts may be degraded. See
air pressure to build before operating the vehicle.
CAUTION
If the red "Warning: Transmission Will Not Shift"
popup appears while the vehicle is in operation,
choose the safest location available to pull the
vehicle off the road. Prepare for the vehicle to be
immobile if the problem cannot be resolved.
If a severe loss of air pressure occurs, a red warning
pop-up will appear and the transmission will not shift.
See Fig. 14.9.
Transmission Prognostics
Some Eaton clutches require the application of
grease for maintenance.
The Eaton transmission prognostics display can be
found by navigating to the maintenance screens in
the driver display. The screen will state if the Grease
Interval is OK or if grease needs to be added. See
Fig. 14.11.
If the system status cannot be read, the message
"SNA" displays.
Allison Automatic
Transmissions
Refer to the Allison website for additional information:
www.allisontransmission.com.
14.13
Fig. 14.8. Wait for
10/21/2019
Fig. 14.11, Eaton Transmission Prognostics
General Information, Allison
Transmissions
Allison transmissions have electronic shift controls
that can be programmed to allow the use of different
numbers of geared speeds. For instance, the
transmission can be programmed to operate as a
4-speed, 5-speed, or 6-speed unit in the "primary"
shift mode. If needed, a "secondary" shift mode can
be programmed to provide another shift configuration
to optimize vehicle use under different operating
conditions. To activate a secondary shift mode, or
other special functions programmed into the
electronic control unit (ECU), briefly depress the
mode switch on the multi-function stalk switch
control; see Fig. 14.1, item 3.
These transmissions use the multi-function stalk
switch to select mode, direction, neutral, low, and to
preselect lower ranges. The current gear, highest
available gear, and mode are shown in the driver
display; see Fig. 14.12. Forward shifts can be made
either automatically or by using Manual mode.
Operation Tips, Allison Transmissions
WARNING
Never shift from neutral (N) to drive (D) or
reverse (R) at engine speeds above idle. The
vehicle will lurch forward or backward, which
could cause property damage and personal
injury.
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