P0743 — Torque Converter Clutch Circuit Electrical
Drive with caution — fix soon.
What P0743 means
This code indicates an electrical problem in the torque converter clutch solenoid circuit, such as an open, short, or out-of-range signal, rather than a purely mechanical fault. It's commonly caused by a failed TCC solenoid, damaged wiring, or a bad connector. Repairs usually involve replacing the solenoid or fixing the wiring, which is often less expensive than internal transmission work.
Common symptoms
- Check Engine light is on
- Torque converter doesn't lock up at cruising speed
- Higher engine RPM than normal on the highway
- Slight reduction in fuel economy
- Possible harsh shifting or transmission running hot
Common causes
- Failed torque converter clutch (TCC) solenoid
- Damaged or corroded wiring in the TCC circuit
- Loose or faulty electrical connector
- Internal transmission electrical fault
- Failing transmission control module (less common)
Typical repair cost
$100 – $1000
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0743 code?
Usually yes, since it's typically an electrical issue and the car still drives, but don't ignore it. The converter may not lock up, adding heat to the transmission, so get it checked soon.
How much does it cost to fix a P0743?
A wiring repair can be quite cheap, while replacing the TCC solenoid generally runs $150 to $600. If the solenoid is internal and requires dropping the pan or valve body, costs can reach $1,000.
Is a P0743 code serious?
It's moderately serious. The car stays drivable, but because the torque converter clutch isn't working right, leaving it unfixed can cause extra wear and heat in the transmission.
Is P0743 an electrical or mechanical problem?
P0743 specifically flags an electrical fault in the torque converter clutch circuit, like a bad solenoid or wiring, which is why diagnosis usually starts with testing the circuit rather than the transmission internals.