OBD-II trouble code
P0744: Torque Converter Clutch Circuit Intermittent
The torque converter clutch circuit is faulting intermittently — locking and unlocking erratically, or throwing a fault that comes and goes. Like all intermittent codes, it's the hardest of the TCC family to catch because the problem often isn't present when you go looking for it.
Quick facts
- System
- Powertrain
- Category
- Transmission / Torque Converter
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $150 – $900
- DIY difficulty
- Shop recommended
What does P0744 mean?
P0744 is the intermittent member of the torque converter clutch family. Where P0740 and P0743 are electrical-circuit faults you can usually measure, P0741 is a steady performance fault, and P0742 is a steady stuck-on fault, P0744 is the one that comes and goes. The PCM sees the TCC circuit or its behavior drop out of spec briefly and then recover — the clutch may cycle in and out of lockup unexpectedly, or the electrical fault may appear only under certain conditions like a particular temperature, a bump, or a specific load. That intermittent nature is the entire diagnostic challenge: the fault may be completely absent while the car sits in the shop.
The most common causes are connection-related rather than a flat-out dead part. A loose or corroded TCC solenoid connector that makes and breaks contact, a wire that's chafed or cracked and only opens when it flexes or heats up, and intermittent electrical noise are the classic offenders. On the hydraulic side, a valve or solenoid that sticks only sometimes — typically from varnish that grabs intermittently — can cause the clutch to cycle erratically and set P0744. Old or contaminated fluid contributes here just as it does with the other TCC codes. A solenoid beginning to fail can also throw an occasional fault before it dies completely.
The symptoms are the familiar lockup complaints, but with an on-again-off-again character: lockup that drops out and returns, a shudder that appears only sometimes, cruise RPM that occasionally jumps, and a check engine light that may come and go. Because the fault is intermittent, the diagnostic strategy mirrors other intermittent codes — chase it with captured data while it's happening rather than a static bench test. Freeze-frame data, a recorded live-data drive that reproduces the condition, and a wiggle-test of the TCC connector and harness while watching the lockup status are the highest-yield tools. Checking fluid condition is still worthwhile because varnish-related sticking is a real cause, but a clean electrical inspection of the connector and wiring is usually where this code is solved.
Common causes
- Loose or corroded TCC solenoid connector making intermittent contact
- Chafed or cracked wire that opens only when it flexes or heats up
- Intermittent electrical noise on the TCC circuit
- TCC solenoid or valve sticking intermittently from varnish
- Old or contaminated transmission fluid causing occasional valve stiction
- Solenoid beginning to fail and dropping out occasionally
- Moisture intermittently bridging connector pins
- Marginal ground shared with the TCC circuit
Symptoms
- Check engine light that may come and go, with P0744 stored
- Torque converter lockup that drops out and returns unexpectedly
- Intermittent shudder between roughly 35 and 55 mph
- Cruise RPM that occasionally jumps higher then recovers
- Fuel economy that varies trip to trip
- Symptoms tied to temperature, bumps, or specific loads
- Fault often absent when the car is stationary in the shop
Diagnostic steps
- 1.Pull freeze-frame data first — it captures the conditions present when the intermittent fault set, which is the best clue for this code.
- 2.Read live data on a drive that reproduces the symptom and watch TCC commanded vs. actual lockup status for erratic cycling.
- 3.Wiggle-test the TCC solenoid connector and harness while watching live data — a glitch during the test localizes a bad connection.
- 4.Inspect the connector for corrosion, backed-out pins, and moisture intrusion.
- 5.Check transmission fluid level and condition; varnish-related intermittent sticking is a real cause and fresh fluid can help.
- 6.Resistance-check the solenoid and check wiring continuity, looking for a reading that drifts or only goes out of spec when flexed or warm.
Repair cost
$150 – $900
Because P0744 is usually an intermittent connection, wiring and connector repairs are a common fix at $100-$300 — sometimes just re-pinning or cleaning a connector. A TCC solenoid replacement runs $250-$700 if the solenoid is dropping out. A transmission fluid service ($150-$300) is worthwhile when varnish-related sticking is suspected. Budget some diagnostic labor, since the hardest part of an intermittent code is catching the fault while it's actually happening.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with transmission shift solenoid replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
Leave this one to a qualified shop. It typically involves emissions-critical components, refrigerant handling, or other work that requires manufacturer-grade tooling, training, or certification. DIY attempts often produce a more expensive problem than the original code.