MasterTuning Fault code dictionary (DTC)

P0740 — Torque Converter Clutch Circuit Malfunction

Severity: Warning Can you drive? With caution: limp mode possible, have it checked soon Make: All makes (OBD-II standard)
MeaningThe engine computer has detected an electrical issue or a performance problem in the circuit that controls the torque converter clutch inside your automatic transmission. This clutch is designed to lock the engine and transmission together at cruising speeds to improve efficiency, and when it fails to engage or show the correct electrical feedback, this code is stored.
FamilyPowertrain (P)

Typical symptoms

The engine RPM might seem slightly higher than usual at highway speeds
The transmission may feel like it is slipping or not shifting smoothly into the highest gear
The check engine light is illuminated on the dashboard

Common causes

Low transmission fluid level or dirty fluid affecting hydraulic pressure
A faulty torque converter clutch solenoid valve
Wiring or electrical connector damage in the transmission harness
Internal wear within the torque converter itself

What to do

Check the transmission fluid level and condition as a first step, as old or low fluid often causes this behavior. You should have a mechanic inspect the electrical connections and test the solenoid soon to prevent further wear inside the transmission.

Frequently asked questions

What does code P0740 mean?

Torque Converter Clutch Circuit Malfunction. The engine computer has detected an electrical issue or a performance problem in the circuit that controls the torque converter clutch inside your automatic transmission. This clutch is designed to lock the engine and transmission together at cruising speeds to improve efficiency, and when it fails to engage or show the correct electrical feedback, this code is stored.

Can I keep driving with code P0740 active?

With caution: limp mode possible, have it checked soon

Common causes — P0740

Low transmission fluid level or dirty fluid affecting hydraulic pressure A faulty torque converter clutch solenoid valve Wiring or electrical connector damage in the transmission harness Internal wear within the torque converter itself

How do you fix code P0740?

Check the transmission fluid level and condition as a first step, as old or low fluid often causes this behavior. You should have a mechanic inspect the electrical connections and test the solenoid soon to prevent further wear inside the transmission.

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