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)

Check Your Fluid First

ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

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Read Transmission Codes

LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

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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

Step-by-Step Diagnostic Procedure

Measure TCC solenoid resistance at the transmission connector
Check TCC solenoid wiring for continuity from TCM to transmission
Inspect the transmission harness connector for corrosion
Check for voltage at the solenoid when TCM commands TCC on
Replace TCC solenoid if electrically faulty

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

Common fix part TCC Solenoid + Internal Harness Kit View on Amazon→ Compare fitment at PartsGeek→

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.