P0744: Torque Converter Clutch Circuit Intermittent (Meaning, Causes, Fixes)
What P0744 means
Cars with an automatic transmission use a torque converter, a fluid coupling between the engine and transmission. At steady cruising speeds the computer applies a torque converter clutch (TCC) to lock the two together so they turn at the same speed, which saves fuel. The clutch is applied with hydraulic fluid that a TCC solenoid directs when the powertrain or transmission control module commands it. OBD-Codes.com says P0744 is set when the transmission control module (TCM) detects a fault with the circuit that operates the TCC solenoid, and its causes stress intermittent opens, shorts and loose connections. RepairPal describes it differently: it says the TCM sets P0744 when it detects that the torque converter failed to lock the engine and transmission together. It is a generic OBD-II code for 1996 and newer vehicles, though repair steps vary by make and model. OBD-Codes.com lists similar codes P0740, P0741, P0742, P0743, P2769 and P2770, and says that if other transmission codes appear alongside P0744, an electrical failure is likely.
Severity: can I keep driving?
Drive with caution, fix soon
Get it checked soon. The two sources disagree on how serious it is: RepairPal rates P0744 Urgent, meaning it can cause severe damage or be unsafe, while OBD-Codes.com lists only the check engine light and a small drop in fuel economy and says it won't affect engine performance. RepairPal adds that the transmission may not shift properly. If the transmission slips, shifts badly or the car behaves oddly when coming to a stop, drive gently and have it diagnosed promptly.
Common symptoms
- Check engine light on, possibly coming and going (OBD-Codes.com)
- Lower fuel economy (both sources; OBD-Codes.com calls it minimal)
- Transmission may not shift properly (RepairPal)
- OBD-Codes.com says the code will not affect engine performance
Likely causes
Roughly most to least common, based on the sources below. Your vehicle may differ.
- Damaged transmission wiring harness, a loose connection, or an intermittent open or short circuit (OBD-Codes.com; RepairPal lists a wiring issue)
- Faulty torque converter clutch (lockup) solenoid (both sources)
- Faulty transmission control module (both sources)
- Torque converter failure (RepairPal)
- The sources differ: OBD-Codes.com treats this as an electrical circuit fault, while RepairPal frames it as the converter failing to lock and also lists the torque converter itself
Diagnostic steps you can do
Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.
- Read all stored codes and note the freeze frame data. If other transmission codes are stored, OBD-Codes.com says an electrical fault is likely, so look at those too.
- Look over the transmission wiring harness and connectors for damage, corrosion or loose connections. OBD-Codes.com suggests wiggling the harness and connectors while testing to help find an intermittent short.
- Check the transmission fluid level and condition, since the clutch is applied hydraulically.
- Check for technical service bulletins (TSBs) for your vehicle; there may be a known fix.
Typical fixes
- Repair damaged, loose or shorted transmission wiring or connectors
- Replace a faulty torque converter clutch (lockup) solenoid
- Replace the torque converter if testing confirms it is failing to lock
- Repair or replace the TCM only after wiring and solenoid tests pass
Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.
🛠 When to call a pro
- The transmission slips, shifts badly or won't settle into top gear
- Diagnosis needs an advanced scan tool to see whether the TCM is commanding the TCC solenoid and what feedback it gets; OBD-Codes.com says a graphing multimeter or oscilloscope may be needed to check the TCM's duty-cycle signal
- Checking the TCC solenoid may require removing the transmission oil pan, and some vehicles combine the solenoid and internal harness as one unit (OBD-Codes.com)
- Wiring checks out and the code keeps returning
Where to buy
Plain search links. Always match parts to your exact year, make, model and engine.
FAQs
What does intermittent mean in P0744?
It means the fault comes and goes rather than being present all the time. OBD-Codes.com points to wiring damage, loose connections and intermittent opens or shorts in the TCC solenoid circuit, which is why wiggling the harness during testing can help find it.
Is P0744 serious?
Sources disagree. RepairPal rates it Urgent and says the transmission may not shift properly, while OBD-Codes.com says it mainly lowers fuel economy and won't affect engine performance. Get it diagnosed soon either way.
Does P0744 mean my torque converter is bad?
Not necessarily. RepairPal lists torque converter failure as one cause, but both sources also list the TCC solenoid and the TCM, and wiring problems are the first thing OBD-Codes.com says to check. Test before replacing the converter.
How much does it cost to fix P0744?
Neither source gives a repair cost. It ranges widely depending on whether the fix is a wiring repair, a solenoid, the TCM or the torque converter, so get a diagnosis and written estimate first.
Sources
Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.