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
DIAGNOSTIC CODE TROUBLESHOOTING
Beginning The Troubleshooting Process
1. Begin troubleshooting by checking the transmission fluid level and ECU input voltage. Check
diagnostic codes by:
Using the shift selector display.
Using the Pro-Link® 9000 diagnostic tool.
2. When a problem exists but a diagnostic code is not indicated, refer to the Performance Complaint
Section for a listing of various electrical and hydraulic problems, their causes, and remedies.
3. If a diagnostic code is found in the ECU memory, record all available code information and clear
the active indicator (refer to Paragraph 52).
4. Test drive the vehicle to confirm a diagnostic code or performance complaint.
If the code reappears, refer to the Diagnostic Code section (Section 6) and the appropriate code
chart. The Diagnostic Code section lists diagnostic codes and their description. Locate the
appropriate troubleshooting chart and follow the instructions.
If the code does not reappear, it may be an intermittent problem. Use the Pro-Link® and the
code display procedure described in Section 5. The code display procedure will indicate the
number of times the diagnostic code has occurred. Refer to the troubleshooting chart for
possible cause(s) of the problem.
Appendix A deals with the identification of potential circuit problems. Refer to Appendix A if a
circuit problem is suspected.
Information concerning specific items is contained in the appendices located in the back of this
manual. The appendices are referred to throughout the manual.
Solenoid locations in the control module are as illustrated in Figure 51. Refer to Figure 51 as
necessary when using the diagnostic code schematics.
Diagnostic Code Schematics
The diagnostic code schematics in this section show wiring for both the optional oil level sensor and
retarder, where applicable. If your transmission is not equipped with an oil level sensor or retarder,
disregard the portions of the schematic pertaining to those optional pieces of equipment. Refer to the
appropriate transmission Service Manual for solenoid replacement procedures.
Wire/Terminal Numbering Scheme
WTEC III wire identification presents the wire number followed by the ECU terminal source
(i.e., 157-S30). This is done to retain the wire number/function assignments from WTEC II and
indicate the ECU connector and terminal origination for WTEC III. If there is a letter suffix following
the wire number, there is a splice between the ECU source and wire destination (i.e., 136A-S16).