WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

FOREWORD -- How to Use This Manual

This manual provides troubleshooting information for Allison Transmission Division, MD/HD/B Series

On-Highway Transmissions. Service Manuals SM2148EN and SM2457EN, plus Parts Catalogs PC2150EN and

PC2456EN may be used in conjunction with this manual.

This manual includes:

Description of the WTEC III electronic control system.

Description of the electronic control system components.

Description of diagnostic codes, system responses to faults, and troubleshooting.

Wire, terminal, and connector repair information.

Specific instructions for using many of the available or required service tools and equipment are not included in

this manual. The service tool manufacturer will furnish instructions for using the tools or equipment.

Additional information may be published from time to time in Service Information Letters (SIL) and will be

included in future revisions of this and other manuals. Please use these SILs to obtain up-to-date information

concerning Allison Transmission products.

This publication is revised periodically to include improvements, new models, special tools, and procedures. A

revision is indicated by a letter suffix added to the publication number. Check with your Allison Transmission

service outlet for the currently applicable publication. Additional copies of this publication may be purchased from

authorized Allison Transmission service outlets. Look in your telephone directory under the heading of

Transmissions -- Truck, Tractor, etc.

Take time to review the Table of Contents and the manual. Reviewing the Table of Contents will aid you in quickly

locating information.

NOTE:

Allison Transmission is providing for service of wiring harnesses and wiring harness components as

follows:

Repair parts for the internal wiring harness and for wiring harness components attached to the shift selector

will be available through the Allison Transmission Parts Distribution Center (PDC). Use the P/N from your

appropriate parts catalog or from Appendix E in this manual. Allison Transmission is responsible for

warranty on these parts.

Repair parts for the external harnesses and external harness components must be obtained from St. Clair

Technologies Inc. (SCTI). SCTI provides parts to any Allison customer or OEM and is responsible for

warranty on these parts. SCTI recognizes ATD, manufacturers, and SCTI part numbers. SCTI provides a

technical HELPLINE at 519-627-1673 (Wallaceburg). SCTI will have parts catalogs available. The SCTI

addresses and phone numbers for parts outlets are:

St. Clair Technologies, Inc.

1050 Old Glass Road

1111 Mikesell Street

c/o Mequilas Tetakawi

Wallaceburg, Ontario, Canada, N8A 3T2

Charlotte, Michigan 48813

Carr. Internationale KM 1969

Phone: (519) 627-1673

Phone: (517) 541-8166

Guadalajara Nogales, KM2

Fax: (519) 627-4227

Fax: (517) 541-8167

Empalme, Sonora, Mexico

Phone: 011-52-622-34661

Fax: 011-52-622-34662

St. Clair Technologies, Inc. stocks a WTEC III external harness repair kit, P/N 29532362, as a source for

some external harness repair parts. SCTI is the source for external harness repair parts.

TRADEMARKS USED IN THIS MANUAL

0021 007