Torque Converter Diagnosis

Torque Converter Diagnosis
Prior to installing a new or remanufactured torque converter, all diagnostic procedures must be followed. This is to prevent the unnecessary installation of a new or remanufactured torque converter. 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 the diagnostic procedures:
- Run on-board diagnostics.
- Repair all non-transaxle related DTCs first.
- Repair all transaxle DTCs.
- Rerun on-board diagnostic to verify repair.
- Carry out the Line Pressure Test.
- Carry out the Stall Speed Test.
- Carry out the diagnostic routines. For additional information, refer to Diagnosis By Symptom. AX4S
- 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 necessary, before installing a new or remanufactured 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; 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 0 position.
4. After normal operating temperature is reached, maintain constant vehicle speed of about 80 km/h (50 mph) and tap the brake pedal with the left foot.
5. Engine rpm should increase when brake pedal is tapped, and decrease about five seconds after the pedal is released. If this does not occur, see the Torque Converter Operation Concerns in Diagnosis By Symptom.
6. If the vehicle stalls in 0 or drive, at idle with vehicle at a stop, move the selector lever to manual 1 position. If the vehicle stalls, refer to Torque Converter Operation Concerns in Diagnosis By Symptom. Repair as necessary. If the vehicle does not stall in 0, refer to Diagnosis By Symptom. AX4S