P0744 Code: Torque Converter Clutch Circuit Intermittent
Lockup control drops in and out: an intermittent TCC circuit, or on some makes a lockup performance fault.
Unverified: this manufacturer-specific definition comes from a single source or varies by model. Confirm it with a brand-specific scan tool.
At a glance
Severity: Moderate
- Meaning
- Torque Converter Clutch Circuit Intermittent
- System
- Transmission · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $80–$2,600
- DIY difficulty
- Moderate
The standard definition of P0744 is an intermittent fault in the torque converter clutch solenoid circuit: the TCM sees the circuit go bad and recover, typically from a loose pin, a chafed wire or a solenoid that fails only now and then. Several manufacturers, including Nissan, Hyundai and Kia on many models, use the same number for a lockup function fault, meaning the converter clutch doesn't hold properly when commanded. In practice both show up the same way on the road: lockup cycles on and off, the tachometer hunts by 100–300 rpm at steady speed, and many drivers feel a shudder at 40–50 mph under light throttle. Because the meaning varies by make, this page is marked as not fully verified; check the exact description with a scan tool that reads the manufacturer's definitions.
Can I keep driving? Usually drivable, but an unstable lockup clutch wears its lining and contaminates the fluid. Keep speeds moderate, avoid towing and get it diagnosed before the shudder becomes constant.
How to read P0744
- P Powertrain
- 0 Generic (SAE)
- 7 Transmission
- 44 Specific fault
Symptoms
- Shudder like driving over rumble strips at 40–50 mph with light throttle
- Tachometer hunting up and down by 100–300 rpm at steady cruise
- Symptoms that come and go with bumps, temperature or rain
- Code that clears itself and returns days later
- Slightly worse highway fuel economy
- Check engine light, sometimes with P0741
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Degraded fluid that has lost its friction modifiers
- Loose pin, corroded terminal or chafed wire in the TCC circuit
- TCC solenoid sticking intermittently
- Glazed or unevenly worn converter clutch lining
- Wear in the valve body's TCC control valve bore
- Engine misfire or driveline vibration mistaken for shudder
- TCM software needing an update
Diagnosis step by step
Find out which definition applies
Read the code with a scan tool that shows the manufacturer's description. 'Circuit intermittent' sends you to the wiring first; 'lock-up function' or 'performance' sends you to fluid, solenoid and converter.
Tools: OBD-II scanner
Rule out misfire and driveline vibration
Check misfire counters during the shudder and note whether the vibration changes with lockup. A converter shudder stops the moment lockup releases; a misfire or a worn U-joint, CV joint or engine mount keeps shaking regardless.
Tools: OBD-II scanner
Wiggle-test the circuit
On a road test at 45–60 mph, watch TCC command, TCC duty cycle and slip while a helper flexes the transmission harness, or tap the connector. A command that stays steady while slip jumps points to hydraulics; a circuit status that flickers points to wiring.
Tools: OBD-II scanner, Flashlight
Inspect the connector and pins
Unplug the transmission connector, check for fluid wicking, green corrosion and loose terminals, and test pin tension. Clean with contact cleaner and make sure the lock tab latches.
Tools: Screwdriver, Flashlight
Replace the fluid – properly
On many units a fluid exchange with the exact specified fluid is the recommended first step for shudder. A pan drain replaces only part of the fluid, so a full exchange or two drain-and-fill cycles are often needed; drive 300–500 miles and recheck.
Tools: Towels & shallow pan, OBD-II scanner
Escalate if it persists
If the shudder returns with fresh fluid and a sound circuit, the next steps are the TCC solenoid and valve body, then the torque converter. A converter replacement requires transmission removal.
Where the parts are
- 1Battery
- 2Alternator
- 3Engine computer (ECM)
- 4CAN bus
- 5Transmission
- 6Wheel speed sensor
- 7High-voltage battery
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Clean, repin or repair TCC wiring and connector | Yes | $80–$300 |
| Transmission fluid exchange with the specified fluid | No | $180–$450 |
| TCM software update | No | $100–$250 |
| Replace TCC solenoid or valve body | No | $350–$1,400 |
| Replace torque converter | No | $1,200–$2,600 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Nissan
On Nissan CVTs, P0744 is described as a torque converter lock-up function fault and often comes with judder at low to moderate speed. Typical steps are a CVT fluid replacement with genuine Nissan CVT fluid and a TCM update; persistent judder can require a valve body, converter or complete CVT.
Field data
| Nissan | 27 | ||
|---|---|---|---|
| Ford | 2 | Edge, Fusion Energi |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
Even though P0744 may come and go, a lit check engine light fails an OBD emissions test, and clearing the code resets the readiness monitors, so drive enough to complete them before testing.
Frequently asked questions
Why does P0744 keep coming back after I clear it?
Intermittent faults only set the code when the condition happens, such as on a bumpy road or with hot fluid. Clearing it just resets the counter; the loose pin or sticking solenoid is still there.
Can a fluid change stop torque converter shudder?
Often, if caught early. Fresh fluid restores the friction properties the converter clutch needs to apply smoothly. If the lining is already glazed or damaged, the shudder returns within a few hundred miles.
How do I know it's converter shudder and not a misfire?
Converter shudder happens only while lockup is applying or applied, typically at steady 40–50 mph, and stops if you press harder on the gas and lockup releases. A misfire usually shows on the misfire counters and doesn't follow lockup.