WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL S ECTION 2 — DEFINITIONS AND ABBREVIATIONS Copyright © 1999 General Motors Corp. 2–1. CHECK TRANS LIGHT When the ECU detects a serious fault, the CHECK TRANS light (usually located on the vehicle instrument panel) illuminates and action is automatically taken to protect operator, vehicle, and the transmission. A diagnostic code will nearly always be registered when the CHECK TRANS light is on; however, not all diagnostic codes will turn on the CHECK TRANS light. Codes related to the CHECK TRANS light are detailed in the code chart (refer to Section 6).
Illumination of the CHECK TRANS light indicates that a condition was detected that requires service attention. Operation may or may not be restricted but even when restricted will allow the vehicle to reach a service assistance location. Depending upon the cause for the CHECK TRANS light illumination, the ECU may or may not respond to shift selector requests. The transmission may be locked in a range. That range will be shown on the shift selector display. Both upshifts and downshifts may be restricted when the CHECK TRANS light is illuminated. Seek service assistance as soon as possible. Each time the engine is started, the CHECK TRANS light illuminates briefly and then goes off.
This momentary lighting shows the light circuit is working properly. If the light does not come on during engine start, request service immediately. 2–2. ALLISON TRANSMISSION DIAGNOSTIC TOOL J-44950 (ATDT™) The new, ATD-developed, diagnostic tool is available to the field. The Allison Transmission Diagnostic Tool (ATDT) is a PC-based, full-feature diagnostic software application supporting WTEC II and WTEC III control systems. Installed on the user’s own PC, it will allow the technician to acquire data from the transmission’s control system and, through the use of embedded Troubleshooting Manuals, conduct systematic troubleshooting of transmission complaints.
The ATDTTM has the following features: The ATDTTM uses a Windows® style graphical user interface (GUI) and includes:
• User selected views of multiple transmission parameters • View Active and Historical Diagnostic Trouble Codes (DTCs) • Graphical instrument panel view of transmission parameters • Strip chart function • User configurable Snapshot function • User configurable Print function • Code driven hotlinks to embedded WTEC II and WTEC III Troubleshooting Manuals • Reprogramming capability (available after satisfying ATD training certification requirement) • Demo Mode which allows the user to practice the program without being connected to a vehicle • Paper copy of the User’s Manual and laminated Job Aid Card • Adobe Acrobat® 4.0 bundled on the CD for reading the Troubleshooting Manuals • Microsoft Media Player® 7.0 bundled on the CD for video display The ATDTTM has been tested with, and is known to operate on PCs with the following configuration*:
• Microsoft Windows 95®, Windows 98® or Windows NT® (4.0) • 50 MB free hard drive disk space • 64 MB of RAM (128 MB for optimal performance) • Pentium II processor • One available COM port or parallel port (both for optimal performance) location. Depending upon the cause for the CHECK TRANS light illumination, the ECU may or may not respond to shift selector requests. The transmission may be locked in a range. That range will be shown on the shift selector display. Both upshifts and downshifts may be restricted when the CHECK TRANS light is illuminated. Seek service assistance as soon as possible. Each time the engine is started, the CHECK TRANS light illuminates briefly and then goes off.
This momentary lighting shows the light circuit is working properly. If the light does not come on during engine start, request service immediately. 2–2. ALLISON TRANSMISSION DIAGNOSTIC TOOL J-44950 (ATDT™) The new, ATD-developed, diagnostic tool is available to the field. The Allison Transmission Diagnostic Tool (ATDT) is a PC-based, full-feature diagnostic software application supporting WTEC II and WTEC III control systems. Installed on the user’s own PC, it will allow the technician to acquire data from the transmission’s control system and, through the use of embedded Troubleshooting Manuals, conduct systematic troubleshooting of transmission complaints.
The ATDTTM has the following features: The ATDTTM uses a Windows® style graphical user interface (GUI) and includes:
• User selected views of multiple transmission parameters • View Active and Historical Diagnostic Trouble Codes (DTCs) • Graphical instrument panel view of transmission parameters • Strip chart function • User configurable Snapshot function • User configurable Print function • Code driven hotlinks to embedded WTEC II and WTEC III Troubleshooting Manuals • Reprogramming capability (available after satisfying ATD training certification requirement) • Demo Mode which allows the user to practice the program without being connected to a vehicle • Paper copy of the User’s Manual and laminated Job Aid Card • Adobe Acrobat® 4.0 bundled on the CD for reading the Troubleshooting Manuals • Microsoft Media Player® 7.0 bundled on the CD for video display The ATDTTM has been tested with, and is known to operate on PCs with the following configuration*:
• Microsoft Windows 95®, Windows 98® or Windows NT® (4.0) • 50 MB free hard drive disk space • 64 MB of RAM (128 MB for optimal performance) • Pentium II processor • One available COM port or parallel port (both for optimal performance)