P0744Torque Converter Clutch Circuit Intermittent
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The torque converter clutch (lock-up) connects pump and turbine mechanically; a solenoid – on/off, pulse-width modulated or proportional – moves a control valve in the valve body. Slip is engine speed minus turbine speed. Manufacturers do not use P0740–P0744 uniformly: Ford uses P0740 for open, P0742 for short to ground and P0744 for short to power, and reports stuck on as P2758. In J2012 P0744 is an intermittent fault in the converter clutch circuit, but no manufacturer document available to us uses it that way: Ford flags a short to power via the driver feedback line after 0.5–5 s with MIL, and Nissan's CVT bulletins treat it as a functional converter fault checked at the valve body and belt. GM does not use it. Short interruptions make the clutch drop out and reapply, and lock-up may be disabled for the trip.
- What you may notice
- Check engine light
- Lock-up missing or jerky at times
- Engine speed jumps when cruising
- Likely causes
- LikelyLoose contact or corrosion at the transmission connector or harness
- PossibleFord: control wire shorted to positive
- PossibleSolenoid with temperature-dependent winding fault
- RareNissan CVT: converter or valve body mechanical
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.