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.

- Carry out the On-Board Diagnostics.

- Repair all non-transaxle related DTCs first.
- Repair all transaxle DTCs.
- Rerun on-board diagnostics to verify repair.

- Carry out the Line Pressure Test. See Special Testing Procedures.
- Carry out the Stall Speed Test. See Special Testing Procedures.
- Carry out Diagnosis by Symptom Routines. See 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 repair as required, before repairing the torque converter.

Operation Test

This test verifies that the torque converter clutch control system and the torque converter are operating correctly.
1. Carry out Self 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 the (D) position.

4. Engine rpm should increase when the brake pedal is tapped, and should decrease about 5 seconds after the brake pedal is released. If this does not occur, refer to Torque Converter Operation Concerns, see Diagnosis By Symptom. If the vehicle stalls in (D) at idle with the vehicle at a stop, move the transaxle range selector lever to the manual 1 position. If the vehicle stalls, see Torque Converter Operation Concerns, in Diagnosis By Symptom. Repair as required. If the vehicle does not stall in the (D) position, see Diagnosis By Symptom.