P0740 Torque Converter Clutch Circuit/Open
P0740 is a generic OBD2 powertrain code. It means “Torque Converter Clutch Circuit/Open” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker.
Ask the AI about P0740 on your car- System
- Powertrain (P)
- Code type
- Generic (SAE)
- Range
- P07xx
- Urgency
- Moderate
What P0740 means
The torque converter clutch locks the engine to the transmission at cruising speed to save fuel. The computer saw the converter still slipping when it commanded a lock-up (P0741 — performance or stuck off), or found a fault in the clutch’s circuit (P0740).
Symptoms
- Engine speed a few hundred rpm higher than usual at a steady highway speed
- Worse highway fuel economy
- Shudder as the converter tries to lock
- A transmission that runs hot
Most likely causes
- A failed torque converter clutch solenoid
- Low, old or wrong transmission fluid
- A sticking valve in the valve body
- Worn clutch material inside the torque converter (high mileage)
- Wiring to the solenoid (P0740)
What to check first
- Check the fluid level and condition
- Check the wiring and the connector at the transmission (P0740)
- Test the solenoid before condemning the torque converter
Can I keep driving with P0740?
Drivable — plan the repair soon
Yes, gently. Ignored for long, it overheats the fluid and can damage the transmission.
What the wording tells you
“Open” means the module found a break in the circuit — no current flowing where there should be. Check the connector (unplugged, corroded, a pushed-back pin), the wire, the fuse and the component’s own coil or element.
How P0740 breaks down
Powertrain. Engine, transmission, fuel and emissions — the codes behind the check engine lamp.
Generic code: defined by SAE, the same on every make.
Transmission.
The specific fault within this range.
Where to look: Transmission
Automatic, dual-clutch and automated manual transmissions: shift and pressure-control solenoids, speed sensors, gear-ratio monitoring, the torque converter clutch, fluid temperature and pressure, range sensors and transfer cases.
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Frequently asked
What does P0740 mean?
P0740 is a generic OBD2 powertrain code. It means “Torque Converter Clutch Circuit/Open” — the same on every make and model, because the definition comes from the SAE J2012 standard rather than from the carmaker. The torque converter clutch locks the engine to the transmission at cruising speed to save fuel. The computer saw the converter still slipping when it commanded a lock-up (P0741 — performance or stuck off), or found a fault in the clutch’s circuit (P0740).
Can I drive with P0740?
Yes, gently. Ignored for long, it overheats the fluid and can damage the transmission.
What causes P0740?
A failed torque converter clutch solenoid; Low, old or wrong transmission fluid; A sticking valve in the valve body; Worn clutch material inside the torque converter (high mileage); Wiring to the solenoid (P0740).
How do I clear P0740?
Fix the cause first, then clear it with any OBD2 scanner or app. Once the fault is gone the car also clears it on its own: the check engine lamp goes off after the self-test passes on three drive cycles in a row, and the stored code ages out after about 40 warm-ups. Clearing without a repair only hides it for a while — and resets the readiness monitors an emissions inspection looks at.
Is P0740 the same on every car?
Yes. P0740 is a generic SAE J2012 code, so its definition is identical on every make and model. What differs is the cause behind it and the repair procedure, which depend on the engine — that’s why the assistant on this page asks for your car.
Guides
Definitions: the generic SAE J2012 codes from Brimly’s offline dictionary (data version 2026.09). Causes and advice are general guidance for all makes — the service information for your car has the last word.