A TCC solenoid (Torque Converter Clutch solenoid) is an electronic valve found in automatic transmissions. It controls the Torque Converter Clutch (TCC), which helps improve fuel efficiency and reduce heat by locking the torque converter at higher speeds.
How It Works
- The torque converter allows the engine and transmission to operate independently at lower speeds.
- When cruising at higher speeds, the TCC solenoid engages the clutch, locking the torque converter so the engine and transmission turn at the same speed.
- This reduces slippage, improves fuel efficiency, and lowers transmission temperature.
Symptoms of a Bad TCC Solenoid
🔸 Erratic shifting or slipping transmission
🔸 Engine stalling at stops (if the TCC remains locked)
🔸 Overheating transmission
🔸 Poor fuel economy
🔸 Check engine light with related trouble codes (e.g., P0740, P0741, P0743)
Replacement Cost
- Parts: $50 – $300
- Labor: $150 – $500 (varies by vehicle and location)
How TCC (Torque Converter Clutch) Solenoids Work
A Torque Converter Clutch (TCC) solenoid is an electronic valve that controls the engagement of the torque converter clutch in an automatic transmission. It helps improve fuel efficiency and transmission performance by locking the torque converter when the vehicle reaches a certain speed.
Step-by-Step Function of a TCC Solenoid
1. Normal Driving (Torque Converter Unlocked)
- When a vehicle is accelerating from a stop, the torque converter allows slip between the engine and transmission, enabling smooth power transfer.
- This slippage allows the vehicle to move without stalling the engine.
2. Activation of the TCC Solenoid
- At higher speeds (typically 40-50 mph), the vehicle’s computer (ECU/TCM) sends a signal to the TCC solenoid.
- The solenoid opens a hydraulic circuit, directing transmission fluid to engage the torque converter clutch.
3. Locking the Torque Converter
- When the TCC engages, the torque converter locks up, creating a direct connection between the engine and transmission.
- This eliminates slippage, improving fuel efficiency and reducing transmission heat.
4. Releasing the Clutch (Unlocking the Torque Converter)
- When the vehicle slows down or extra power is needed (e.g., accelerating or climbing a hill), the ECU disengages the TCC solenoid.
- The torque converter unlocks, allowing slippage again to prevent engine stalling or rough shifting.
Why is the TCC Solenoid Important?
✅ Improves Fuel Economy – Prevents power loss due to slippage.
✅ Reduces Transmission Heat – Less friction means cooler operation.
✅ Enhances Driving Smoothness – Prevents unnecessary shifting and strain.
Common Symptoms of a Failing TCC Solenoid
🔴 Shuddering or Harsh Shifting – Especially at highway speeds.
🔴 Engine Stalling When Stopping – If the clutch remains locked.
🔴 Transmission Overheating – Due to excessive slippage.
🔴 Check Engine Light (Codes: P0740, P0741, P0743, etc.)
Road Runner Converters Offers Many Torque Converter Replacements
Road Runner Converters offers many torque converters for sale online. We offer GM Torque Converters, Ford Torque Converters, Diesel Torque Converters, Towing Torque Converters, Street Torque Converters and more.
