Torque Converter: Testing and Inspection

Torque Converter Diagnosis
Prior to installing a new torque converter, all diagnostic procedures must be followed. This is to prevent the unnecessary installation of good 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 Concern.
3. Verify the Concern - Carry out the Torque Converter Clutch Operation Test; refer to Torque Converter Operation Test.
4. Carry out Diagnostic Procedures.
^ Run on-board diagnostics. See On-Board Diagnostics with diagnostic tool. Refer to Diagnostics. Diagnostics
- Repair all non-transmission related DTC's first.
- Repair all transmission DTC's.
- Rerun on-board diagnostics to verify repair.
^ Carry out the Line Pressure Test. Refer to Special Testing Procedures. Line Pressure Test Special Testing Procedures
^ Carry out the Stall Speed Test. Refer to Special Testing Procedures. Stall Speed Test Special Testing Procedures
^ Carry out the Diagnosis by Symptom Index. 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 all possible components that may cause or contribute to the symptom. Check each component listed, diagnose and service as necessary before servicing the torque converter.

Torque Converter Operation Test
This test verifies that the torque converter clutch control system and the torque converter are operating correctly.
1. Carry out the Quick Test. See On-Board Diagnostics with diagnostic tool. Refer to Diagnostics. Diagnostics
Check for DTC's. Refer to the Diagnostic Trouble Code Charts. Diagnostic Trouble Code Tests and Associated Procedures
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. After normal operating temperature is reached, maintain a constant vehicle speed of about 80 km/h (50 mph) and tap the brake pedal with the left foot.
5. The engine rpm should increase when the brake pedal is tapped, and decrease about 5 seconds after the pedal is released. If this does not occur, refer to Torque Converter Operation Concerns in Diagnosis By Symptom. Diagnosis By Symptom
6. If the vehicle stalls in (D) or manual 2 at idle with vehicle at a stop, move the transmission range selector lever to manual 1 position. If the vehicle stalls, refer to Diagnosis By Symptom, Torque Converter Operation Concerns. Diagnosis By Symptom
Repair as necessary. If the vehicle does not stall in (D), refer to Diagnosis By Symptom. Diagnosis By Symptom