400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2002-01-1336 New Electronic Control System for Off-Highway Transmissions Robert L. Crum and Lawrence A. Gutsch Allison Transmission Divisi on, General Motors Corp. Reprinted From: Transm ission and Driveline Systems for Off-Highway (SP-1770) SAE International Off-Highway Congress co-located with CONEXPO-CON/AGG Las Vegas, Nevada March 19-21, 2002Downloaded from SAE International by University of Auckland, Saturday, August 04, 2018The appearance of this I SSN code at the bottom of this page indicates SAE’s co nsent that copies of the paper may be made for personal or internal use of spec ific clients. This consent is given on the condition, however, that the copier pay a per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sections 107 or108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying forgeneral distribution, for advertising or promotional purposes, for creating new collective works, or forresale. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department.To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wr itten permission of the publisher. ISSN 0148-7191 Copyright © 2002 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by whic h discussions will be printed with the paper if it is p ublished in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be c onsidered for presentation or publication thr ough SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in theGlobal Mobility DatabaseDownloaded from SAE International by University of Auckland, Saturday, August 04, 20182002-01-1336 New Electronic Control System for Off-Highway Transmissions Robert L. Crum and Lawrence A. Gutsch Allison Transmission Division, General Motors Corp. Copyright © 2002 Society of Automotive Engineers, Inc. ABSTRACT A third-generation transmission electronic control system has been developed for the family of Allison off-highway transmissions. The new controls are identified by the acronym CEC2, which stands for Commercial E lectronic Controls 2 . The CEC2 controls will be phased into all off- highway transmissions and they will eventually replace the second-generation electronic control system known as Commercial E lectronic C ontrols 1 (CEC1). The new transmission controls are primarily targeted toward mobile equipment applications, but they can also be used in stationary equipment applications. INTRODUCTION This paper contains a brief history of the first and second- generation transmission control systems followed by a summary of the various steps that were followed in the development of the new control system. A description of the new or enhanced features of the new controls is presented along with how the features can be interfaced and utilized in an end product. The service-related aspects of the new control system are also addressed. A typical off-highway transmission is shown in figure 1. Figure 1: Typical off-highway transmissionHISTORY In 1971, the first-generation electronic controls were introduced for automatic shifting of Allison off-highway