Q: Intermittently, the transmission will start shifting poorly, and the gauges will start to behave erratically.

Shortly after purchasing the car the above mentioned issues began happening. First a warning chime would sound, then the vehicle security light would come on, followed by a power steering warning message being shown. Immediately at this point the speedometer, tachometer, and fuel gauge all began to bounce around.at first this was all that would happen. Then the power steering started go out intermittently, and finally the transmission would shift poorly if at all. I took the vehicle to the dealership where I was told by their mechanic that a new TCM was needed to resolve the issue. After paying for them to replace and program the TCM the car seemed to run fine, floral one day. Now the issues have begun again just as described above. And the dealership wants to charge me 50 dollars an hour to attempt to diagnose the problem. If you could give me an idea of anything else that could be causing this issue I would greatly appreciate it. Thank you.

My car has 124000 miles.
My car has an automatic transmission.