While my wife was driving on the Pennsylvania Turnpike, her vehicle suddenly shut off without warning. Since there was no shoulder, she had to coast to find a safe place to pull over. All the dashboard lights came on, indicating what appeared to be an electrical issue. She attempted to restart the vehicle several times, but only received a message stating, Battery low, needs charge. She contacted OnStar, expecting prompt assistance, but the experience was far from whats advertised. She waited a total of 45 minutes just to speak with someone, only to be transferred to another representative. Despite having paid for OnStar services when we purchased the vehicle, they refused to cover the towing charges because she was on a private highway, forcing her to pay out of pocket for a service we had already purchased. During this time, it was extremely cold and windy. My 5-year-old daughter and wife waited about an hour and a half for the tow truck to arrive, and then an additional two hours while the driver secured the vehicle onto the flatbed. Since the car was completely dead, they had no heat the entire time. When they stepped out of the car so the tow truck driver could load it, they discovered they couldnt get back inside’the doors wouldnt open due to the lack of power. This entire ordeal was not only frustrating but incredibly unsafe for them. Having the vehicle shut down without warning on a busy highway, especially with our young child in the car, was terrifying for them. After our vehicle was at the dealership for a week, we were informed that the engine needs to be replaced. We were shocked to learn that this is a common issue with GMs 6.2 engines. To make matters worse, there is no estimated timeframe for the repair because the engine is on backorder. For reference, the truck only has 24,000 miles on it and has been exclusively serviced by authorized Cadillac dealers. This experience has been both disappointing and deeply concerning.