Torque Converter Diagnosis: Notes

Prior to installing a new torque converter, all diagnostic procedures must be followed. This is to prevent the unnecessary installation of good torque converters. Only after a complete diagnostic evaluation can the decision be made to install a new or remanufactured torque converter.

Begin with the normal diagnostic procedures as follows:

1. Preliminary Inspection.
2. Know and Understand the Customer Concern.
3. Verify the Concern - Carry out the Torque Converter Clutch Operation Test; refer to TORQUE CONVERTER OPERATION TEST  in this article.
4. Carry out Diagnostic Procedures.
   • Run on-board diagnostics. See On-Board Diagnostics with Diagnostic Tool . Refer to DIAGNOSTICS  in this article.
     • Repair all non-transmission related DTCs first.
     • Repair all transmission DTCs.
     • Rerun on-board diagnostics to verify repair.
   • Carry out the Line Pressure Test. Refer to SPECIAL TESTING PROCEDURES  in this article.
   • Carry out the Stall Speed Test. Refer to SPECIAL TESTING PROCEDURES  in this article.
   • Carry out the Diagnosis by Symptom Index. Refer to DIAGNOSIS BY SYMPTOM  in this article.
     • Use the index to locate the appropriate routine that best describes the symptom(s). The routine will list all possible components that may cause or contribute to the symptom. Check each component listed, diagnose and service as necessary before servicing the torque converter.