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 converter. After a complete diagnostic evaluation can a 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 Operation Test
4. Carry out diagnostic procedures:
- Run OBD (On-Board Diagnostic). Refer to Diagnostics Diagnostics.
- Repair all non-transmission related DTCs first.
- Repair all transmission DTCs.
- Rerun OBD (On-Board Diagnostic) test to verify repair.
- Carry out Line Pressure Test. Refer to Special Testing Procedures Special Testing Procedures.
- Carry out Stall Speed Test. Refer to Special Testing Procedures Special Testing Procedures.
- Carry out diagnostic routines. Refer to Diagnosis By Symptom Diagnosis By Symptom.
- Use the index to locate the appropriate routine that best describes the symptom(s). The routine will list 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 Operation Test
This test verifies the TCC (Torque Converter Clutch) control system and the torque converter are operating correctly.
1. Carry out self-test and check for DTCs.
2. Connect the scan tool and monitor engine rpm.
3. Bring the engine to normal operating temperature by driving the vehicle at highway speeds with the selector lever in the (D) position.
4. If the vehicle stalls in (D) at idle with the vehicle at a stop, move the selector lever to manual L position. If the vehicle stalls, see Torque Converter Operation Concerns, refer to Diagnosis By Symptom Diagnosis By Symptom. Repair as required. If the vehicle does not stall in (D), refer to Diagnosis By Symptom Diagnosis By Symptom.