im running a stock GTP TC and my PCM has the TCC at 50% increase for lockup. just noticed when cruising at a 40-45mph, letting of then on again that i noticed the TC isnt engaging. i can tell because while my right foot is on the gas and if i tap the brakes just gently to engage it i dont hear it unlocking as well as my RPMs dont increase a bit. if i lower the MPH to like 35mph then apply steady-light throttle it'll engage in 3rd gear. is this a sign that my TC is going bad or is it something else?