P0743 moderate

Torque Converter Clutch Circuit Electrical

The P0743 code means the vehicle's onboard diagnostic system has detected: Torque Converter Clutch Circuit Electrical. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$150 - $800 (parts and labor)
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Common Symptoms

  • Check Engine Light illuminated
  • TCC does not engage
  • Decreased fuel economy
  • Possible transmission shudder

Probable Causes (Ranked by Likelihood)

  • Open or short in TCC solenoid wiring Very High
  • Failed TCC solenoid coil High
  • Corroded TCC solenoid connector Moderate
  • TCM TCC driver circuit fault Low

Common Fixes by Vehicle

What techs usually find when diagnosing P0743 on specific vehicles — tap your vehicle for the fix and the exact part:

1996-2013 GM 4L60E & Chrysler automatics hard DIY

TCC solenoid electrical fault means the circuit is open or shorted. Test the solenoid resistance and check the internal harness/connector pass-through on the transmission — these wear and chafe. Replacing the TCC solenoid and the internal wire harness together is the durable repair. Use new fluid and a filter on reassembly.

Labor: 2-4 hours

Frequently Asked Questions

Can I drive with code P0743?

Drive short distances only. Torque Converter Clutch Circuit Electrical can cause severe transmission damage if ignored.

What is the most common fix for P0743?

The most common fix is replacing the affected solenoid. In some cases, a transmission fluid flush and solenoid replacement resolves the issue. Internal torque converter or valve body damage requires more extensive repair.

Can I replace the solenoid myself?

On some vehicles, shift solenoids are accessible by removing the transmission pan. On others, the valve body must be removed. This is a moderate to hard DIY job requiring transmission fluid drainage and careful reassembly.

Mechanics Guide Step-by-step diagnosis

Step-by-Step Diagnostic Procedure

  1. Measure TCC solenoid resistance at the transmission connector

  2. Check TCC solenoid wiring for continuity from TCM to transmission

  3. Inspect the transmission harness connector for corrosion

  4. Check for voltage at the solenoid when TCM commands TCC on

  5. Replace TCC solenoid if electrically faulty

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)

Commonly Affected Vehicles

  • 2003-2015 Ford F-150
  • 2004-2016 Chevrolet Silverado
  • 2005-2017 Toyota Tacoma
  • 2002-2014 Honda Odyssey

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