Flow of Diagnosis

Prior to torque converter replacement all diagnostic procedures must be followed. This is to prevent the unnecessary replacement of good torque converters. Only after a complete diagnostic evaluation can the decision be made to replace the torque converter. Begin with the normal diagnostic procedures as follows:
1. Preliminary inspection.
2. Know and understand the customer's concern.
3. Verify the concern. Perform the Torque Converter Clutch Operation Test.
4. Run on-board diagnostics.
^ Repair all non-transmission related first.
^ Repair all transmission
^ Rerun on-board diagnostic to verify repair.
5. Perform Line Pressure Test.
6. Perform Stall Speed Test.
7. Perform Diagnosis by Symptom Routines.
^ 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 required, before servicing the torque converter.