To Next Page

To Previous Page

LEVER SHIFT SELECTOR

General Description. The lever shift selector (refer to Figure 9 and Figure 10) is

an electro-mechanical control. Typical lever positions are:

• R (Reverse)

• N (Neutral)

• D (Drive)

• Some number of lower forward range positions

Emergency Vehicle Series transmissions can be programmed to have up to six

forward ranges (seven for the 4700/4800 EVS). Shift selector positions should

agree with the programming of the TCM/ECU unit.

The lever selector includes the following:

• HOLD OVERRIDE button

• MODE button

• Digital display

• DISPLAY MODE/DIAGNOSTIC button

HOLD OVERRIDE Button. The lever shift selector has three locked positions to

prevent accidentally selecting R (Reverse), N (Neutral), or D (Drive). Select

R (Reverse), N (Neutral), or D (Drive) by pressing the HOLD OVERRIDE

button and moving the lever to the desired position. Once D (Drive) is selected,

lower forward range positions may be selected without pressing the

HOLD OVERRIDE button.

MODE Button. The MODE button can allow the driver to enable a secondary

shift schedule, PTO enable, or other special functions that have been programmed

into the TCM/ECU unit at the request of the OEM. For example, an emergency

vehicle OEM may have provided a secondary shift schedule for improved fuel

economy. The name of the special function (ECONOMY) appears on the MODE

ID label adjacent to the MODE button. Pressing the MODE button activates the

ECONOMY shift schedule and illuminates the MODE INDICATOR (LED).

When the Diagnostic Display Mode has been entered, the MODE button is used

to view and toggle through diagnostic code information. After viewing the ﬁrst

diagnostic code which appears in the digital display, press the MODE button to

view the 2

diagnostic code logged. Repeat this procedure to view the 3

and 5

code positions. The code displayed is active if the MODE INDICATOR

(LED) is illuminated.

NOTE: Visually check the digital display whenever the lever is moved

to be sure the range selected is shown. N should appear in the digital

displayiftheN (Neutral) button is pressed.

Allison Transmission Emergency Vehicle Series User Manual

Questions and Answers: