P0740 — P0740 — Torque Converter Clutch Circuit / Solenoid
Drivable short-term, but fix now to avoid damage.
What P0740 means
P0740 means there's a problem in the torque converter clutch circuit or its solenoid. This clutch normally 'locks' the engine and transmission together at cruising speed for efficiency. When it fails, you can lose fuel economy, feel slipping, and risk overheating the transmission fluid.
Common symptoms
- Check engine light on
- Drop in fuel economy
- Slipping sensation at cruising speed
- Engine RPM higher than normal on the highway
- Transmission running hot
Common causes
- Faulty torque converter clutch solenoid
- Damaged wiring or connector to the solenoid
- Low or dirty transmission fluid
- Worn torque converter
- Internal transmission valve body issues
- Faulty transmission control module
Typical repair cost
$150 – $1200
Varies by vehicle and root cause.
Frequently asked questions
Can I drive with a P0740 code?
Short trips are usually okay, but driving long-term can overheat the fluid and worsen wear. It's safer to have it diagnosed soon to avoid a pricier torque converter repair.
How much does it cost to fix P0740?
Replacing the solenoid or fixing wiring often runs $150-$500. If the torque converter itself needs replacing, costs can climb to $600-$1,200 due to the labor involved.
Is P0740 serious?
It's a high-priority code. While the car may still drive, ignoring it can lead to overheating and damage to the transmission, turning a moderate fix into a major one.
What is the torque converter clutch?
It's a component that locks the engine directly to the transmission at higher speeds to save fuel and reduce heat. P0740 means the circuit controlling that lockup isn't working right.