P0740 Code: Torque Converter Clutch Circuit (Malfunction)
P0740 means a fault in the torque converter clutch (lock-up) circuit — the clutch that locks the converter for efficiency at cruise.
- Applies to
- All OBD-II vehicles (any make or model)
- Est. repair cost
- $100 – $1,500
- Time to fix
- 1-3 hours
What it means
Common causes are low/dirty transmission fluid, a failed TCC solenoid, or torque-converter wear. This is a generic OBD-II powertrain code defined in the SAE J2012 standard, so it applies to virtually any 1996-or-newer OBD-II vehicle — cars, trucks, and modern fuel-injected motorcycles — from any manufacturer (Toyota, Honda, Ford and the rest). Read it with any OBD-II scanner; the meaning is the same across brands, though the exact repair can vary by engine.
Symptoms
- Check engine light on
- Shuddering at cruise; poor economy
- Higher-than-normal RPM at speed
How to fix it
- 1
Check fluid and the TCC solenoid
1. Check the transmission fluid level and condition. 2. Test the torque converter clutch solenoid and wiring. 3. Service/repair as needed, then clear the code.
Frequently asked questions
Is P0740 expensive?
It depends — a solenoid or fluid service is moderate, but a worn torque converter is costlier. Start with fluid and the solenoid.
Last updated July 16, 2026
Guidance only — always consult a qualified professional or the official service manual before carrying out repairs.