Torque Converter Clutch Circuit Intermittent
The P0744 code indicates an intermittent fault in the torque converter clutch (TCC) circuit. The TCC locks the torque converter to improve fuel economy at highway speeds. An intermittent signal suggests a loose connection, damaged wiring, or a failing TCC solenoid. This can cause erratic shifting, reduced fuel economy, and potential transmission overheating.
1. Symptoms You Will Notice
- Check Engine Light on
- Erratic shifting or shuddering during gear changes
- Reduced fuel economy
- Transmission slipping or overheating
2. Most Common Causes
- Faulty torque converter clutch solenoid
- Damaged or corroded wiring/connectors in the TCC circuit
- Low transmission fluid level or dirty fluid
- Internal transmission mechanical failure
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Check transmission fluid level and condition; top off or replace if necessary.
Step 3: Inspect wiring and connectors for damage, corrosion, or loose connections.
Step 4: Test TCC solenoid resistance and operation using a multimeter or scan tool.
Step 5: Perform a pressure test on the TCC circuit to verify hydraulic function.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause transmission overheating and further damage. Short trips to a repair shop are acceptable if the transmission is not slipping severely.
How much does it cost to fix?▼
Repair costs vary from $150 for a simple wiring repair to $400 or more for solenoid replacement. If internal transmission damage is found, costs can exceed $1,500.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.