HELP! 4L60E problems....
Due to the torque converter not locking at highway speeds, the computer senses that it's not locking up, and sends it into fail safe mode, my tranny guy tells me. This apparently causes the tranny to run full pressure, and causes the shifts to be hard as hell. So, I'm bringing it in Monday to get the lockup valve checked out. Thanks for reading!
My guess would be on the torque converter clutch being fried rather than the lock up solinoid in the transmission going bad.
If it's going into some sort of failsafe mode it should be setting the check engine light.

