ABBREVIATIONS (CONTINUED)

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

DEFINITIONS AND ABBREVIATIONS

23.

ABBREVIATIONS (CONTINUED)

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.

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

World Transmission

Infinity -- Condition of a circuit with higher resistance than can be measured, effectively

an open circuit.

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