The TP sensor suggests the throttle plate angle. If the driver accelerates to wide-open up throttle, the TCM disengages the TCC to downshift. This fluid coupling permits the motor to continue running even though the auto is stationary, preventing it from stalling and boosting torque when accelerating from the quit. https://torqueconverterclutch68887.ttblogs.com/13640154/torque-converter-clutch-can-be-fun-for-anyone