DEFINITIONS AND ABBREVIATIONS
W T E C I I I E L E C T R O N I C C O N T R O L S T R O U B L E S H O O T I N G M A N U A L
0011 00-23
OLS
Oil Level Sensor — Electronic device (optional) on control module for indicating
transmission fluid level.
PCCS
PROM Calibration Configurator System
PCMCIA
Personal Computer Memory Card International Association — Memory device for use
with Pro-Link® containing Allison Transmission programming and diagnostics.
PROM
Programmable Read Only Memory
PSS
Primary Shift Selector — Main shift selector in a two-selector control system.
PTO
Power Takeoff
PWM Solenoid
Pulse Width Modulated Solenoid — Solenoids are controlled by pulse width modulation.
Solenoid control of clutch pressures is based on the solenoid’s duty cycle. Duty cycle is
determined by the ratio of solenoid’s on-time to off-time.
RMR
Retarder Modulation Request — Signal from a retarder control device.
RPR
Return to Previous Range — Diagnostic response in which the transmission is
commanded to return to previously commanded range.
SCI
Serial Communication Interface — Used to transmit data and messages between the
diagnostic tool and the ECU and other systems such as electronically-controlled engines.
SOL OFF
All SOLenoids OFF
SPI
Serial Peripheral Interface — The means of communication between the microprocessor
and the interface circuits.
SSS
Secondary Shift Selector — Alternate shift selector in a two-selector control system.
TID
TransID — A feature which allows the ECU to know the transmission configuration and
provide the corresponding calibration required.
TPS
Throttle Position Sensor — Potentiometer for signaling the position of the engine fuel
control lever.
V
Version — Abbreviation used in describing ECU software levels.
VDC
Volts Direct Current (DC)
VIM
Vehicle Interface Module — A watertight box containing relays and fuses — interfaces the
transmission electronic control system with components on the vehicle.
VIW
Vehicle Interface Wiring — Interfaces ECU programmed input and output functions with
the vehicle wiring.
Volt
Unit of electrical force.
VOM
Volt/ohmmeter
WOT
Wide Open Throttle
WT
World Transmission
×
Infinity — Condition of a circuit with higher resistance than can be measured, effectively
an open circuit.
2–3.
ABBREVIATIONS (CONTINUED)
