P0740 — Torque Converter Clutch Circuit
Moderate severityWhat it means
P0740 is stored when the engine control unit sees a fault involving the torque converter clutch (TCC) circuit. The torque converter clutch locks the converter at cruising speed to save fuel; a circuit fault can cause shudder, stalling or poor economy. The control unit has flagged this circuit or signal as outside its normal operating range.
Common symptoms
- Shudder or vibration at cruising speed
- Stalling when coming to a stop
- Poor fuel economy or RPM that won't settle
Likely causes
- A wiring, connector or ground problem in the circuit
- A failed sensor or actuator in the circuit
- Faulty TCC solenoid
- Low/dirty fluid or a valve-body problem
What to check first
- Inspect the connector and wiring for damage, corrosion or loose pins
- Check TCC lock-up in live data at steady cruise
- Inspect fluid condition and the solenoid connector
Can you keep driving?
Often drivable, but stalling at stops is a safety concern and fluid issues can worsen — diagnose soon.
Scan, log and diagnose with MechanicAI
Plug a Bluetooth OBD2 adapter into your car and let MechanicAI turn raw data into answers:
- Scan, read and clear fault codes in seconds
- Inspect every sensor with live data
- Create instant logs and automatic trip records
- And above all — analyze it all with AI for the most likely cause and clear next steps.
Related codes
All information, explanations and guidance on this page are general preliminary information only. They are estimates and may be entirely wrong, incomplete or inaccurate, or may not apply to your vehicle at all. Never take any action based on this content alone — do not decide to keep driving, clear codes, replace parts, repair or otherwise work on your vehicle based only on what you read here. In every case, and for any final decision, you must consult qualified technical personnel (a professional mechanic, an authorized service centre or an engineer) and obtain their approval before acting. MechanicAI accepts no liability or responsibility whatsoever for any damage, fault, injury, loss or outcome that may arise — directly or indirectly — from using or relying on this information, for any reason and under any circumstances. By using this page you acknowledge and accept these terms.