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DTC codes / P07xx · Transmission / P0744

P0744Torque Converter Clutch Circuit Intermittent

P0744 indicates that the powertrain control module (PCM) has detected an intermittent fault in the torque converter clutch (TCC) circuit, meaning the electrical signal or hydraulic response is not consistent. The PCM monitors the TCC solenoid command and the resulting engine speed change; when the expected drop in engine speed does not occur or the circuit resistance fluctuates, it sets this code.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyIntermediate
AreaTransmission

Symptoms you may notice

  • Often no symptoms besides the warning light, especially if the intermittent fault has not recurred recently.
  • Occasional shudder or vibration during light acceleration at highway speeds when the TCC tries to engage.
  • Unexplained drop or fluctuation in fuel economy due to the clutch not locking up consistently.
  • Intermittent engine speed flare or surge while cruising at steady speed, as the clutch slips or disengages.
  • Harsh or delayed gear shifts in some transmissions when the TCC circuit fault affects shared hydraulic control.
  • A stored pending code that may clear itself after several drive cycles without recurrence.

Common causes, most likely first

  1. Damaged, chafed, or corroded wiring in the TCC solenoid circuit, especially near connectors or where the harness bends.
  2. Failing TCC solenoid with intermittent coil resistance or sticking valve inside the solenoid.
  3. Contaminated or degraded automatic transmission fluid (ATF) causing erratic hydraulic response and solenoid sticking.
  4. Poor electrical connection at the transmission pass-through connector or PCM harness, often due to water intrusion or loose pins.
  5. Faulty PCM driver for the TCC circuit, though this is less common than wiring or solenoid issues.
  6. Internal transmission wear, such as a leaking TCC apply piston seal or valve body wear, causing intermittent clutch apply.
  7. Aftermarket electrical accessories or poor grounds interfering with the TCC circuit signal.

How to diagnose and fix it

  1. Scan all modules for stored and pending codes, then record freeze-frame data to see when the intermittent fault occurred.
  2. Inspect the TCC solenoid circuit wiring and connectors for chafing, corrosion, or loose pins, and perform a wiggle test while monitoring live data.
  3. Check transmission fluid level and condition; service the fluid and filter if it is dark or contaminated, following the manufacturer's procedure.
  4. Measure TCC solenoid resistance at the transmission connector and compare to specification; replace the solenoid if out of range or intermittent.
  5. Use a scan tool to command the TCC on and off while monitoring engine speed and TCC slip data to confirm the fault is electrical versus hydraulic.
  6. If electrical checks pass, perform a transmission pressure test and inspect the valve body for sticking valves or worn TCC apply components.
  7. After repairs, clear codes and complete a relearn or drive cycle to verify the code does not return.

Intermittent TCC faults that fool technicians

  • A P0744 can be set by a momentary glitch in the TCC circuit that never recurs, so always check for pending codes and freeze-frame data before condemning parts.
  • Corroded or loose pins at the transmission pass-through connector are a frequent hidden cause, especially on vehicles exposed to road salt or high humidity.
  • The code does not always mean the TCC solenoid is bad; a sticking valve body or degraded fluid can cause the same intermittent symptom without any electrical fault.
  • Some vehicles set P0744 when the TCC is commanded off during deceleration and the PCM sees an unexpected slip, which can be caused by a failing engine coolant temperature sensor or misfire affecting torque calculations.
  • Aftermarket remote starters or alarm wiring tapped into the transmission harness can introduce intermittent signals that mimic a TCC circuit fault.

Can I keep driving with P0744?

You can usually continue driving with P0744 because the fault is intermittent and the transmission remains functional, but avoid heavy towing or aggressive acceleration until it is diagnosed. If you notice shuddering, slipping, or the code becomes consistent, have it inspected promptly to prevent transmission damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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