Diagnostic Procedure

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.

The normal diagnostic procedure is as follows:

1. Preliminary inspection.

2. Know and understand the customers concern.

3. Verify the concern:

- Perform the Torque Converter Clutch Operation Test

4. Perform diagnostic procedures:

a. 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.

b. Perform Line Pressure Test

c. Perform Stall Speed Test

d. 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.