Diagnose right in your browser — plug in an ELM327 and the site reads your car itselfProgram for Windows and macOS — all-module scan on any make
ENRUDEPLES

P0740 — Torque Converter Clutch Circuit Malfunction

moderate

What it means

The electrical circuit that controls the torque converter lockup clutch solenoid is open, shorted or drawing an implausible current. With lockup unavailable the converter always slips, so engine revs stay higher at cruise, fuel consumption rises and the transmission fluid runs hotter. Some vehicles also lose overdrive or show slight speed hunting on the motorway.

Likely causes (most common first)

  1. Failed torque converter clutch solenoid
  2. Broken, chafed or shorted wiring to the solenoid
  3. Corroded or water damaged transmission case connector
  4. Dirty transmission fluid or a clogged filter blocking the solenoid
  5. Faulty driver stage in the transmission control module

Can you drive with it?

You can keep driving, but expect higher fuel use and hotter transmission fluid; fix it before long motorway trips.

This is the generic meaning. What about your car?

The same code has different typical culprits on different engines. Tell the AI your make, model and year — it will rank the causes for your exact car and give you a check order.

Diagnose this code for my car