Today I was attempting to pass an Audi on the freeway doing about 75 or so. Instead of the transmission shifting, the RPMs climbed to redline and the car never found a gear until I let up off the gas. This rarely happens, maybe 4 times since I've had the car (1 time on old tranny, 3 times on new). What could be causing this? TCU malfunction? Something internal to the tranny? It seems to me that the car is looking to shift into 2nd as max speed for that gear is around 80mph.