Torque Converter Diagnosis

Torque Converter Diagnosis
Prior to torque converter installation, all diagnostic procedures must be followed. This is to prevent the unnecessary installation of new or remanufactured 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's Concern
3. Verify the Concern - carry out the torque converter operation test.
4. Carry out Diagnostic Procedures:
^ Run on-board diagnostics.
- Repair all non-transmission related DTCs first.
- Repair all transmission DTCs.
- Rerun On-Board Diagnostic to verify repair.
- Carry out Line Pressure Test. Line Pressure Test
- Carry out Stall Speed Test. [1][2]Component Tests and General Diagnostics
- Carry out diagnostic routines. Diagnostic 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 repair as required, before installing a new torque converter.

Torque Converter Clutch (TCC) Operation Test
This test verifies that the TCC control system and the torque converter are operating correctly.
1. Carry out Quick Test, refer to the tester manual. Check for DTCs.
2. Connect a tachometer to the engine.
3. Bring the engine to normal operating temperature by driving the vehicle at highway speeds for approximately 15 minutes in (D) position.
4. If the vehicle stalls in (D) at idle with vehicle at a stop, move the selector lever to manual L position. If the vehicle stalls, refer to torque converter operation concerns. Repair as required. If the vehicle does not stall in (D), refer to Diagnosis By Symptom. Torque Converter Operation Concerns 250/350-252/352 Diagnosis By Symptom