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 C defective

3. Input shaft (mainshaft) speed sensor defective

4. Output shaft (countershaft) speed sensor defective

5. Shift cable broken or out of adjustment

6. Connection between shift cable and transmission or shift lever is worn

7. Foreign material in separator plate orifice

8. Torque converter clutch piston defective

9. Torque converter check valve defective

10. Lock-up shift valve defective

11. Lock-up control valve defective

12. Lock-up timing valve defective

Also check for:

- Check for a stored DTC, and check for loose connections.
- Inspect the shift solenoid valve function with the HDS.
- Check for a seized shift solenoid valve, and inspect the O-rings.
- Inspect the A/T clutch pressure control solenoid valve 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.
- Check for a loose shift cable at the shift lever and the transmission control lever.
- Check for a clogged orifice in the separator plate. If the orifice is clogged, remove it and clean the separator plate orifice.
- Check the speed sensor installation.
- Inspect the sensor O-ring for wear and damage.
- Check the line pressure.
- Replace the torque converter.
- Check the torque converter check valve and the lock-up shift valve in the main valve body for free movement, and check the valve springs for wear and damage.
- Check the lock-up control valve in the regulator valve body for free movement, and check the valve spring for wear and damage.