P0740 — Torque Converter Clutch Circuit/Open

P0740: Torque Converter Clutch Circuit/Open — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

Torque Converter Clutch Circuit/Open. Basic catalogue definition; diagnostic details have not yet been reviewed.

Affected system: Powertrain

Symptoms

  • Erratic shifts; increased consumption and transmission heating.

Possible causes

  • Faulty TCC solenoid or damaged wiring; converter faults may coexist.

What to check

  • Inspect TCC control wiring and connectors before evaluating the converter.

Also written as: P0740-00, P074000, PO740 (some scan tools add the fault-type byte, e.g. -00).