P0744 indicates that the torque converter clutch (TCC) circuit is intermittently losing continuity or signal. The transmission control module (TCM) detects an unstable voltage or resistance in the TCC solenoid circuit, which can cause the lock‑up clutch to engage or disengage unpredictably.
The solenoid that controls lock‑up may have an internal open/short that appears intermittently.
Chafed, corroded, or loose wires and pins can create an intermittent connection.
Debris or insufficient fluid level can affect solenoid operation and cause erratic signals.
Restricted hydraulic passages can prevent proper solenoid actuation, leading to intermittent circuit feedback.
Rare; a defective driver circuit inside the control module can mimic an intermittent solenoid fault.
No. The control module is rarely the root cause; most intermittent TCC circuit faults are due to the solenoid, wiring, or fluid condition.
Driving is possible but the transmission may slip, overheat, or lose overdrive, which can lead to further damage if not addressed.
If the code is caused by contaminated or low fluid, a proper fluid and filter service can resolve it; otherwise the underlying electrical or mechanical fault remains.
Most manufacturers specify 10‑20 Ω at 20 °C; values outside this range indicate a faulty solenoid.