Engine-Codes - Toyota - P0743 Toyota

P0743 Toyota Code - Torque Converter Clutch Circuit Electrical

- Code Popularity: 11,404 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
Table of contents

|What are the Possible Causes of the Code P0743 Toyota?

  • 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 P0743 Toyota Code?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

|Code P0743 Toyota 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 P0743 Toyota?

Labor: 1.0

The cost to diagnose the P0743 Toyota code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.

Does your Toyota have Safety Recalls? → Check here

|What are Code P0743 Toyota Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

|What Does the P0743 Toyota Code Mean?

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).

P0743 Toyota Code - Torque Converter Clutch Circuit Electrical

|Need more Information on the P0743 Toyota Code?

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

|Need Help with the P0743 Toyota Code?

Get the P0743 Toyota code diagnosed by a professional: Find a repair shop in your area