AutoCodes – Mitsubishi – P0743 Mitsubishi

P0743 Mitsubishi Code - Torque Converter Clutch System Circuit Malfunction

Quick Answer

The Torque Converter Clutch (TCC) is designed to increase efficiency by mechanically coupling the engine to the transmission. Common causes include Dirty transmission fluid, Low transmission fluid level, 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: P0743 Mitsubishi indicates Torque Converter Clutch System Circuit Malfunction.
Common causes: Common causes include Dirty transmission fluid, Low transmission fluid level, 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.

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 13,867

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 27, 2021

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

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

Code P0743 Mitsubishi Description

The Torque Converter Clutch (TCC) is designed to increase efficiency by mechanically coupling the engine to the transmission. The 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 condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up. By performing a voltage drop test, the ECM detects that the Torque Converter Clutch (TCC) solenoid circuit is open or shorted and sets the Diagnostic Trouble Code (DTC).

OBDII Code P0743 Mitsubishi - Torque Converter Clutch System Circuit Malfunction - AutoCodes.com — P0743 Mitsubishi Code - Torque Converter Clutch System Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0743 Mitsubishi?

Dirty transmission fluid
Low transmission fluid level
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 P0743 Mitsubishi?

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

This is an electrical problem code. Could be a problem with the harness to the Torque Converter Clutch (TCC) solenoid, the TCC solenoid connector, or the TCC solenoid itself.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0743 Mitsubishi 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 P0743 Mitsubishi code?

Need more information on how to fix the P0743 Mitsubishi code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0743 Mitsubishi 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 P0743 Mitsubishi Code

What does the OBDII code P0743 mean for a Mitsubishi vehicle?

P0743 indicates a malfunction in the Torque Converter Clutch (TCC) solenoid circuit, which controls the locking and unlocking of the torque converter in the transmission.

What are the common symptoms of code P0743 in a Mitsubishi?

Symptoms can include transmission slipping, poor fuel efficiency, difficulty shifting, and illumination of the check engine light.

What causes code P0743 in a Mitsubishi?

Common causes include a faulty TCC solenoid, damaged wiring or connectors, transmission fluid contamination, or issues with the vehicleâ€™s Powertrain Control Module (PCM).

Can driving with code P0743 cause damage to my vehicle?

Yes, prolonged driving with P0743 can lead to increased transmission wear, poor fuel economy, and potential overheating of the transmission.

How do I diagnose code P0743 in a Mitsubishi?

Diagnosis typically involves checking the TCC solenoid, inspecting wiring and connectors for damage, testing the PCM, and verifying transmission fluid condition.

What repairs can fix code P0743 in a Mitsubishi?

Repairs may include replacing the TCC solenoid, repairing damaged wiring, cleaning or flushing the transmission fluid, or reprogramming or replacing the PCM.

How much does it cost to repair code P0743 on a Mitsubishi?

Costs vary depending on the repair, ranging from $100 to $500 for solenoid or wiring repairs, and potentially more if PCM replacement is necessary.

Can low transmission fluid cause code P0743?

Yes, low or contaminated transmission fluid can affect the TCC solenoidâ€™s operation and trigger the code.

How can I prevent code P0743 from occurring in the future?

Regular transmission maintenance, including fluid changes and inspections, can help prevent issues with the TCC solenoid and related components.

Is a professional mechanic needed to fix code P0743 on a Mitsubishi?

While some repairs, such as checking fluid levels, can be done by the owner, diagnosing and repairing solenoid or PCM issues typically requires a professional mechanic.