2008 Cadillac CTS electrical system problems

The car has had 7 batteries replaced. It has been towed three times to two different dealerships. When the failure occurs the door lock, the engine will not start, lights will not work, the car is completely dead. The last time my wife went one mile and the lights,radio, air conditioning and doors locked and would not open. She could not get the key out of the ignition. The door was opened and the car sat for two hours. When she went back to the car everything worked like nothing happened.

I was driving in a parking garage so my speed was about 5-10MPH when the whole system shut down. The car stopped moving and all of the system warnings popped off (ABS, stabiltrack,engine). The car would not turn back on. I had it towed to the shop where I was told that it was an electrical problem. The PCM was replaced and I was told that the problem was fixed. Cost was approx $200. After the original system shut down, I was driving on an exit ramp to the interstate when once again the whole system shut down.