Powertrain, generic · Transmission

P0744 Torque Converter Clutch Circuit Intermittent

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Loose contact or corrosion at the transmission connector or harness
Ford: control wire shorted to positive
Solenoid with temperature-dependent winding fault
Nissan CVT: converter or valve body mechanical

Symptoms

  • Check engine light
  • Lock-up missing or jerky at times
  • Engine speed jumps when cruising

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

torque converter clutch solenoidtorque convertertransmission valve bodytransmission control module

Related codes

P0740P0741P0742P0743P2763

References: newtonnet.co.uk, fordservicecontent.com, static.nhtsa.gov, static.nhtsa.gov.