AutoCodes – Infiniti – P0744 Infiniti

P0744 Infiniti Code - Torque Converter Clutch Circuit Intermittent

Quick Answer

The Torque Converter Clutch (TCC) 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 (TCC) 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: P0744 Infiniti indicates Torque Converter Clutch Circuit Intermittent.
Common causes: Common causes include Low transmission fluid level, Dirty transmission fluid, Faulty Torque Converter Clutch (TCC) 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 27,442

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 Sep 29, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0744 Infiniti Description

The Torque Converter Clutch (TCC) 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.
The 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 conditions, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.
The Diagnostic Trouble Code (DTC) P0744 is detected when A/T cannot perform lock-up even if the electrical circuit is good.

OBDII Code P0744 Infiniti - Torque Converter Clutch Circuit Intermittent - AutoCodes.com — P0744 Infiniti Code - Torque Converter Clutch Circuit Intermittent

What does this mean?

What are the Possible Causes of the DTC P0744 Infiniti?

Low transmission fluid level
Dirty transmission fluid
Faulty Torque Converter Clutch (TCC) 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 P0744 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 does this mean?

Code Tech Notes

When a transmission solenoid is working intermittently, in most cases, the problem is not the electrical part of the solenoid; the problem is foreign material obstructing the mechanical function of the solenoid or the flow of the fluid through the transmission valve body. If the transmission fluid is very dirty, it's recommended to change the transmission fluid and, if possible, remove the transmission pan for further diagnosis. Excessive debris or metal particles on the transmission pan could be an indication that there is a mechanical transmission failure, and that the transmission will need to be rebuilt or replaced.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0744 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 P0744 Infiniti code?

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Information for Specific Infiniti Models

P0744 2003 Infiniti G35 — Torque Converter Clutch Circuit Intermittent
P0744 2004 Infiniti G35 — Torque Converter Clutch Circuit Intermittent
P0744 2005 Infiniti G35 — Torque Converter Clutch Circuit Intermittent
P0744 2006 Infiniti G35 — Torque Converter Clutch Circuit Intermittent

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 P0744 Infiniti Code

1. What are the common symptoms of OBDII code P0744 in an Infiniti related to the Torque Converter Clutch Circuit Intermittent?

The common symptoms include erratic shifting, engine stalling at idle, poor fuel economy, and the Check Engine light illuminating on the dashboard.

2. What are the possible causes of OBDII code P0744 in an Infiniti?

The code P0744 in an Infiniti is typically caused by a faulty torque converter clutch solenoid, wiring issues, low transmission fluid level, or a malfunctioning torque converter.

3. How serious is OBDII code P0744 in an Infiniti?

While the car may still be operational with this code, it is important to address it promptly to prevent further damage to the transmission and ensure optimal performance and fuel efficiency.

4. Can I continue driving my Infiniti with OBDII code P0744 present?

It is not advisable to continue driving the vehicle with this code present, as it can lead to further transmission issues and potentially leave you stranded.

5. How can I diagnose OBDII code P0744 in my Infiniti?

Diagnosing this code typically involves using a scan tool to retrieve the specific code, checking the transmission fluid level and condition, inspecting the wiring and connectors, and testing the torque converter clutch solenoid.

6. Can I repair OBDII code P0744 in my Infiniti myself?

While some DIY enthusiasts may attempt to repair this code themselves, it is recommended to consult with a professional mechanic or technician due to the complexity of transmission systems.

7. How much does it cost to repair OBDII code P0744 in an Infiniti?

The cost of repairing this code can vary depending on the underlying cause, but it may range from a few hundred to over a thousand dollars, including parts and labor.

8. Are there any preventive maintenance tips to avoid OBDII code P0744 in an Infiniti?

Regularly servicing your transmission, checking the fluid levels, and addressing any abnormal symptoms promptly can help prevent issues that may trigger this OBDII code.

9. Can a faulty torque converter cause OBDII code P0744 in an Infiniti?

Yes, a malfunctioning torque converter can contribute to the triggering of OBDII code P0744, as it affects the operation of the torque converter clutch circuit.

10. How long does it take to repair OBDII code P0744 in an Infiniti?

The repair time for this code can vary depending on the specific cause and the availability of parts, but it may take a few hours to a full day for a skilled mechanic to diagnose and address the issue.