Allison B 400 - Diagnostic Code Troubleshooting

Copyright © 1998 General Motors Corp. 6–17
DIAGNOSTIC CODES
WTEC II ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL
6–6. DIAGNOSTIC CODE TROUBLESHOOTING
A. 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 Section 6).
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 6. 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.
NOTE: Information concerning specific items is contained in the appendices located in the back of this
manual. The appendices are referred to throughout the manual.
B. Solenoid Locations
Solenoid locations in the control module are as illustrated in Figure 6–1. Refer to Figure 6–1 as
necessary when using the diagnostic code schematics.
Figure 6–1. Control Module Solenoid Location
D (C4)
C (C3)
N (SIGNAL)
MD 3070
ONLY
E (C5)
J (C6)
G (FORWARD – ON MAIN VALVE BODY)
A (C1)
C3 PRESSURE
SWITCH
RIGHTLEFT
BACK
FRONT
F (LOCKUP)
B (C2)
V01594