So I’ve been having trouble with my car, it started when it got cold out that the car wouldn’t start and said auto-park disabled and the car wouldn’t start since it thought it wasn’t in park. But now it’s doing it all the time.
U0101 is the PCM reporting that it didn't receive a Bus Message from the TCM for approximately two to five seconds. TCM for the 8-speed transmission is attached to the valve body and can not be serviced separately. So I can see why the dealership diagnosed the problem as the valve body.
There's not a lot of components listed as possible causes for U0101. You can get U0101 along with other diagnostic codes that are related to battery voltage, ignition or VIN messages. But you didn't list any other codes. I guess it's worth getting the battery load tested just to confirm it's not a problem.
The other problem can be CAN Bus (controller area network) circuits being shorted or open. You need a CAN Bus analyzer to see the signals on the CAN Bus but you can check for wiring harness connections to see if any are loose, frayed/cracked, corroded, etc... The other possible causes listed are the BCM (body control module not configured correctly), the TCM (which you replaced) and the PCM.