• A TCC piston built into the torque converter operates during TCC control. When hydraulic pressure is applied to the TCC piston, the TCC clutch engages to mechanically connect the pump impeller to the turbine runner. The TCC mechanism achieves excellent fuel economy as a result of no loss in drive force transmission due to torque converter slippage. In addition, precise hydraulic control is made possible by a multi-plate clutch equipped with an independent piston housing. With the adoption of this mechanism, the achievable range of TCC control has widened dramatically.