Trouble codes › P0740

P0740 Torque Converter Clutch Solenoid Circuit/Open

Transmission

P0740 means there's an electrical fault in the torque converter clutch solenoid circuit, so the converter won't lock up at cruise.

The torque converter clutch locks the engine to the transmission at cruising speed to save fuel. P0740 means the transmission computer found an electrical fault in the solenoid that controls it.

Can I keep driving? Yes, but get it fixed soon.

Usually drivable, but fuel economy drops and the transmission runs hotter at highway speed. Get it fixed soon, and avoid towing.

Common causes

  1. A failed torque converter clutch solenoid
  2. Damaged wiring or a corroded connector (inside or outside the transmission)
  3. A blown fuse feeding transmission solenoids

Symptoms

  • Higher engine rpm at highway speed
  • Worse fuel economy
  • Check-engine light

What to check first

  1. Check the transmission solenoid fuse.
  2. Inspect the transmission's external connector for fluid or corrosion.
  3. Measure the solenoid's resistance through the connector as your service information describes.
  4. Repair wiring or replace the solenoid (often inside the transmission pan).

What does P0740 mean on your vehicle?

The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.

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Related codes

General guidance for P0740 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.