AutoCodes – Generic – P0740

P0740 Code - Torque Converter Clutch Malfunction

Quick Answer

The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty torque converter clutch solenoid valve. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0740 indicates Torque Converter Clutch Malfunction.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty torque converter clutch solenoid valve.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 46,962

How popular is this code, among other codes? Medium

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 08, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0740 Description

The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter.
Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.

OBDII Code P0740 - Torque Converter Clutch Malfunction - AutoCodes.com — P0740 Code - Torque Converter Clutch Malfunction

What does this mean?

What are the Possible Causes of the DTC P0740?

Low transmission fluid level
Dirty transmission fluid
Faulty torque converter clutch solenoid valve
Torque converter clutch solenoid valve harness is open or shorted
Torque converter clutch solenoid valve circuit poor electrical connection

How to Fix the DTC P0740?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0740 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0740 code?

Need more information on how to fix the P0740 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0740 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0740 Acura — Transmission Lock-Up Control System Fault
P0740 Audi — Torque Converter Clutch Circuit Malfunction
P0740 BMW — Torque Converter Clutch Circuit Open
P0740 Buick — Torque Converter Clutch Malfunction
P0740 Cadillac — Torque Converter Clutch Malfunction
P0740 Chevrolet — Torque Converter Clutch Malfunction
P0740 Chrysler — Torque Converter Clutch Circuit
P0740 Dodge — Torque Converter Clutch Circuit
P0740 Ford — Torque Converter Clutch Solenoid Circuit
P0740 GMC — Torque Converter Clutch Malfunction
P0740 Honda — Transmission Lock-Up Control System Fault
P0740 Hummer — Torque Converter Clutch Malfunction
P0740 Hyundai — Torque Converter Clutch Solenoid Valve
P0740 Infiniti — Torque Converter Clutch Solenoid Valve
P0740 Isuzu — Torque Converter Clutch Solenoid Valve Circuit Fault
P0740 Jeep — Torque Converter Clutch Circuit
P0740 KIA — Damper Clutch Solenoid System
P0740 Mazda — Torque Converter Clutch Solenoid Valve Circuit Malfunction
P0740 Mercedes-Benz — Torque Converter Clutch Malfunction
P0740 MINI — Torque Converter Clutch Circuit Open
P0740 Mitsubishi — Torque Converter Clutch System Malfunction
P0740 Nissan — Torque Converter Clutch Solenoid Circuit Fault
P0740 Pontiac — Torque Converter Clutch Malfunction
P0740 RAM — Torque Converter Clutch Circuit
P0740 Saturn — Torque Converter Clutch Malfunction
P0740 Subaru — Torque Converter Clutch System Malfunction
P0740 Suzuki — Torque Converter Clutch Circuit Malfunction
P0740 Volkswagen — Torque Converter Clutch Circuit Malfunction

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0740 Code

1. What are the common symptoms of OBDII code P0740 (Torque Converter Clutch Malfunction)?

The common symptoms of P0740 include engine stalling at idle, slippage or shuddering during acceleration, and decreased fuel efficiency.

2. What are the possible causes of OBDII code P0740?

The main causes of P0740 include a faulty torque converter clutch solenoid, low transmission fluid levels, a malfunctioning torque converter, or wiring issues in the transmission system.

3. Can I continue to drive my vehicle with OBDII code P0740?

It is not recommended to drive your vehicle with P0740 for an extended period as it can lead to further damage to the transmission. It is best to have the issue diagnosed and repaired promptly.

4. How is OBDII code P0740 diagnosed?

P0740 is typically diagnosed using a scan tool to retrieve the trouble code from the vehicle's computer. Additional testing may involve checking the transmission fluid level, inspecting the torque converter clutch solenoid, and conducting a road test to confirm the symptoms.

5. How can I repair OBDII code P0740?

Repairing P0740 may involve replacing the torque converter clutch solenoid, addressing any transmission fluid leaks, checking and potentially replacing the torque converter, or fixing any wiring issues in the transmission system.

6. Can a DIY enthusiast fix OBDII code P0740 at home?

While some aspects of diagnosing and repairing P0740 may be within reach of a skilled DIY enthusiast, dealing with transmission-related issues can be complex. It is recommended to seek professional help to ensure the problem is properly diagnosed and repaired.

7. Is OBDII code P0740 a serious issue?

P0740 can lead to significant transmission problems if left unaddressed. Ignoring the issue can cause further damage to the transmission components, leading to costly repairs down the line.

8. How much does it typically cost to repair OBDII code P0740?

The cost of repairing P0740 can vary depending on the specific cause of the issue and the labor rates in your area. It is recommended to get multiple quotes from reputable repair shops to compare prices.

9. Can OBDII code P0740 be triggered intermittently?

Yes, P0740 can sometimes be triggered intermittently, especially if the issue is related to a faulty solenoid or intermittent wiring problem. It is still important to address the problem promptly to avoid potential transmission damage.

10. Will resetting the OBDII code P0740 clear the issue?

Resetting the code may temporarily clear the check engine light, but it will not fix the underlying problem causing P0740. It is crucial to diagnose and repair the issue to prevent further transmission damage.