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 Condition - Perform the Torque Converter Operation Test.
4. Perform Diagnostic Procedures.
^ Run on-board diagnostics.
^ Repair all non-transmission related Diagnostic Trouble Codes (DTCs) first.
^ Repair all transmission DTCs.
^ Rerun on-board diagnostic to verify repair.
^ Perform Line Pressure Test.
^ Perform Stall Speed Test.
^ Perform Diagnostic Routines.
^ Use the Diagnosis by Symptom 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 repair as required before changing the torque converter.