Torque Converter Clutch Circuit Performance / Stuck Off

The torque converter clutch (TCC) physically locks the converter so there's no slip between engine and transmission at cruise speed — better fuel economy and less heat. The TCM commands lockup and watches engine RPM vs trans input RPM to confirm. If RPM stays higher than input speed when lockup is commanded, the converter is slipping and P0741 sets. Common causes: failed lockup solenoid, worn TCC friction material, contaminated fluid, or a sticking valve in the valve body.

Slip RPM between engine and transmission input exceeds the threshold (typically >100 RPM slip) when the TCC is commanded fully applied.

Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.

1. 1Check trans fluid level and condition. Burnt smell = friction material is shedding.
2. 2Watch slip RPM PID during a steady cruise with TCC commanded on. Quantify the slip.
3. 3Bidirectional command the TCC solenoid — listen for click, watch slip drop.
4. 4If solenoid clicks but slip stays — internal trans (converter, valve body, or seals).

• Failed TCC solenoid
• Worn torque converter clutch friction material
• Contaminated / burnt transmission fluid
• Stuck valve in valve body
• Internal trans leak (worn seal / sealing rings)
• Bad input or output speed sensor

$300 (solenoid) to $3,500+ (converter + trans rebuild).