The TP sensor indicates the throttle plate angle. If the driver accelerates to large-open up throttle, the TCM disengages the TCC to downshift. There are many means of locking the torque converter clutch. These differences are purpose of the hydraulic circuit controlling the clutch actuation. Lack of good torque converter https://torqueconverterclutch97317.vblogetin.com/39694930/torque-converter-clutch-for-dummies