Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
A/T Control System: Lock-up Control: Notes
The torque converter clutch piston in the torque converter is engaged to eliminate torque converter slip to increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque converter clutch solenoid valve, which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases the torque converter clutch piston.
Lock-up Operation Condition Table (QR25DE Models)
| Select lever | D position | 3 position | 2 position | |
|---|---|---|---|---|
| Gear position | 5 | 4 | 3 | 2 |
| Lock-up | x | - | - | - |
| Slip lock-up | - | - | - | - |
Lock-up Operation Condition Table (VQ40DE Models)
| Select lever | D position | 3 position | 2 position | |
|---|---|---|---|---|
| Gear position | 5 | 4 | 3 | 2 |
| Lock-up | x | x | - | - |
| Slip lock-up | - | - | x | - |
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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