1-14. POWERTRAIN (CONT)
Figure 1-9. Powertrain (Cont)
b. Transmission. The vehicle is equipped with a fully automatic, electronically controlled,
seven-speed close-ratio Allison transmission Model MD3070PT (2, Figure 1-9). The
WTEC II Transmission ECU Pushbutton Shift Selector (TEPSS) has a velcro cover and the
WTEC III Transmission Pushbutton Shift Selector (TPSS) does not have a velcro cover.
(1) The WTEC II TEPSS (7) or WTEC III TPSS (7) is located in the instrument panel,
to the Operators left.
(2) The transmission defaults to Neutral (N) whenever electrical power is removed from
the vehicle. When electrical power is first supplied to the vehicle, the WTEC II TEPSS
or WTEC III TPSS will momentarily display MODE ON in the LED display. MODE ON
display will disappear and N N will be left in the LED display. This lets you know that
the transmission is in highway mode and Neutral range (N).
(3) The Drive (D) gear selection is used for normal driving conditions. The transmission
will engage 2nd gear when D is selected and the vehicle is stopped. The LED display
will illuminate 7 2, indicating that the transmission is in 2nd gear and there are seven
forward gears available. Low gear (1st gear), is available only through manual selection
by pressing the down arrow button until 1 1 is displayed in the LED display. You may
manually downshift or upshift to a lower or higher gear range as required. However, the
transmission will not downshift to a lower gear if the engine speed is too high for the
gear selected. Selecting a specific gear; for example, 3rd; will prevent the transmission
upshifting past the selected gear.