AutoCodes – Suzuki – P0740 Suzuki

P0740 Suzuki Code - Torque Converter Clutch Circuit 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 Suzuki indicates Torque Converter Clutch Circuit 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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 5,539

How popular is this code, among other codes? Low

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0740 Suzuki 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 Suzuki - Torque Converter Clutch Circuit Malfunction - AutoCodes.com — P0740 Suzuki Code - Torque Converter Clutch Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0740 Suzuki?

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 Suzuki?

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 Suzuki 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 Suzuki code?

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

Need Help with the Code?

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

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 Suzuki Code

1. What does the OBDII code P0740 mean for a Suzuki?

P0740 indicates a Torque Converter Clutch (TCC) Circuit Malfunction, meaning the transmission control module has detected an issue with the TCC engaging or disengaging properly.

2. What are the common symptoms of the P0740 code on a Suzuki?

Symptoms may include decreased fuel efficiency, transmission overheating, slipping gears, rough shifting, or the check engine light turning on.

3. What can cause the P0740 code in a Suzuki?

Common causes include a faulty torque converter clutch solenoid, damaged wiring or connectors in the TCC circuit, low or dirty transmission fluid, or internal transmission issues.

4. Can I drive my Suzuki with the P0740 code?

Driving with this code is not recommended for extended periods, as it can lead to poor fuel economy, transmission damage, or overheating.

5. How do I fix the P0740 code on my Suzuki?

Repairs may involve replacing the TCC solenoid, repairing damaged wiring, flushing and refilling the transmission fluid, or addressing internal transmission problems.

6. How much does it cost to fix the P0740 code in a Suzuki?

Repair costs vary depending on the issue, ranging from $150-$400 for solenoid replacement to more expensive repairs if internal transmission damage is present.

7. Can low transmission fluid cause the P0740 code?

Yes, low or dirty transmission fluid can prevent proper TCC operation and trigger the P0740 code.

8. Will clearing the P0740 code fix the problem?

No, clearing the code will only reset the check engine light temporarily. The underlying issue must be diagnosed and repaired to prevent the code from returning.

9. How is the P0740 code diagnosed in a Suzuki?

A mechanic will typically use a scan tool to verify the code, inspect the TCC solenoid and circuit, check the transmission fluid condition, and perform a test drive to monitor TCC operation.

10. Can a bad torque converter cause the P0740 code?

Yes, a faulty torque converter can prevent proper clutch engagement and trigger the P0740 code, though this is less common than solenoid or wiring issues.