TORQUE CONVERTER CLUTCH (TCC) OPERATION


BHE051318901T17

TCC release

• The TCM stops driving the TCC solenoid (OFF) when TCC release is determined.

TCC engagement

• When the TCM determines TCC engagement, the TCM gradually increases the duty ratio energizing the TCC solenoid, and gradually drains the oil pressure in the torque converter F chamber.

• The TCC piston slowly presses against the converter cover, and the TCC engages smoothly.

1
Torque converter F chamber
2
Torque converter pressure
3
Torque converter pressure (drain)
4
Oil cooler
5
TCC solenoid
6
Pilot pressure
7
TCC control valve

Determination of TCC inhibition

• The TCC is inhibited when any of the following conditions are met.

– ATF temperature is low.
– Throttle valve is closed.
– Failure is detected by diagnosis function.