AutoCodes – Infiniti – P0740 2004 Infiniti G35

P0740 2004 Infiniti G35 Code - Torque Converter Clutch Solenoid Valve

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 2004 Infiniti G35 indicates Torque Converter Clutch Solenoid Valve.
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 3,675

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 Dec 04, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0740 2004 Infiniti G35 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 2004 Infiniti G35 - Torque Converter Clutch Solenoid Valve - AutoCodes.com — P0740 2004 Infiniti G35 Code - Torque Converter Clutch Solenoid Valve

What does this mean?

What are the Possible Causes of the DTC P0740 2004 Infiniti G35?

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 2004 Infiniti G35?

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 2004 Infiniti G35 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.

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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 2004 Infiniti G35 Code

1. What does the OBDII code P0740 mean on a 2004 Infiniti G35?

P0740 indicates a malfunction in the Torque Converter Clutch (TCC) solenoid circuit, which affects the transmission's ability to lock the torque converter properly.

2. What are the symptoms of code P0740 on a 2004 Infiniti G35?

Common symptoms include poor fuel efficiency, transmission overheating, slipping gears, difficulty accelerating, or the Check Engine Light being illuminated.

3. What causes the P0740 code to appear on a 2004 Infiniti G35?

Possible causes include a faulty TCC solenoid, low or dirty transmission fluid, damaged wiring or connectors in the TCC circuit, or a failing torque converter.

4. Can driving with code P0740 damage my 2004 Infiniti G35's transmission?

Yes, driving with this code can lead to increased transmission wear, overheating, and potential long-term damage if not addressed promptly.

5. How can I fix the P0740 code on my Infiniti G35?

Repairs may include replacing the TCC solenoid, repairing damaged wiring or connectors, flushing and refilling the transmission fluid, or, in severe cases, replacing the torque converter.

6. How do I diagnose the P0740 code on a 2004 Infiniti G35?

A proper diagnosis involves scanning for trouble codes, inspecting the TCC solenoid and its wiring, checking the transmission fluid condition, and testing the torque converter's operation.

7. Is a faulty torque converter a common cause of the P0740 code in a 2004 Infiniti G35?

While less common than solenoid or wiring issues, a failing torque converter can cause this code, especially if the problem persists after addressing other components.

8. What does the Torque Converter Clutch solenoid do in a 2004 Infiniti G35?

The TCC solenoid controls the engagement of the torque converter clutch, improving fuel efficiency and reducing heat in the transmission.

9. Can low transmission fluid trigger the P0740 code on a 2004 Infiniti G35?

Yes, low or contaminated transmission fluid can cause the TCC solenoid to malfunction, leading to the P0740 code.

10. How much does it cost to repair the P0740 code on a 2004 Infiniti G35?

Repair costs vary depending on the issue, ranging from $150â€“$400 for solenoid replacement to $1,000â€“$2,500 for torque converter replacement, excluding diagnostics.