Component Tests

Torque Converter Diagnosis
Prior to torque converter replacement, all diagnostic procedures must be followed. This is to prevent the unnecessary replacement of good torque converters. Only after a complete diagnostic evaluation can the decision be made to install a new 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.
4. Carry out diagnostic procedures:
- Check for DTCs.
- repair all non-transmission related DTCs first.
- repair all transmission DTCs.
- carry out Line Pressure Test.
- carry out Stall Speed Test.
- carry out 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 repairing the torque converter.

Torque Converter Operation Test
This test verifies that the TCC control system and the torque converter are operating correctly.
1. Check for DTCs. Refer to Diagnostic Trouble Code Charts.
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. 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 pedal is released. If this does not occur, refer to Torque Converter Operation Concerns in the Diagnosis by Symptom Chart.
6. If the vehicle stalls in the "D" position or Manual 2 at idle with vehicle at a stop, move the selector lever to Manual position. If the vehicle stalls, refer to Torque Converter Operation Concerns. Repair as required. If the vehicle does not stall in the "D" position, refer to Diagnosis by Symptom.