AutoCodes – Infiniti – P0740 Infiniti

P0740 Infiniti 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 Infiniti 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.

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 16,754

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
Comments
Add Comment

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

Code P0740 Infiniti 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 Infiniti - Torque Converter Clutch Solenoid Valve - AutoCodes.com — P0740 Infiniti Code - Torque Converter Clutch Solenoid Valve

What does this mean?

What are the Possible Causes of the DTC P0740 Infiniti?

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 Infiniti?

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 Infiniti 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 Infiniti code?

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

Need Help with the Code?

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

Information for Specific Infiniti Models

P0740 2003 Infiniti G35 — Torque Converter Clutch Solenoid Valve
P0740 2004 Infiniti G35 — Torque Converter Clutch Solenoid Valve
P0740 2005 Infiniti G35 — Torque Converter Clutch Solenoid Valve
P0740 2006 Infiniti G35 — Torque Converter Clutch Solenoid Valve

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.