Torque Converter Clutch Does Not Engage

Torque converter clutch does not engage

Diagnostic Procedure:

1. Shift solenoid valve D defective

2. A/T clutch pressure control solenoid valve A defective

3. Input shaft (mainshaft) speed sensor defective

4. Output shaft (countershaft) speed sensor defective

5. Torque converter clutch piston defective

6. Torque converter check valve defective

7. Lock-up shift valve defective

8. Lock-up control valve defective

Also check for:

- Check for a stored DTC, and check for loose connections.
- Test the solenoid valve function with the HDS.
- Inspect the A/T clutch pressure control solenoid valve body gasket, the ATF feed pipes, and the O-rings for wear and damage.
- Inspect shift solenoid valve D for seizure, and the O-rings for wear and damage.
- Check the input shaft (mainshaft) speed sensor and the output shaft (countershaft) speed sensor installation. Inspect the sensor O-ring for wear and damage.
- Replace the torque converter assembly.
- Check the torque converter check valve in the regulator valve body.
- Check the lock-up shift valve in the regulator valve body.
- Check the lock-up control valve in the main valve body.