On [XXX], around 1:00, I was driving normally on the highway. I remember using autopilot, and the speed limit was 55 mph, but I'm not very sure. At that time, it was raining heavily, and I was following the car in front, not doing anything else. Suddenly, I noticed that the Tesla car turned sharply to the left by itself! I couldn't control it. Let me repeat: the Tesla car suddenly turned left by itself. I instinctively grabbed the steering wheel, turned in the opposite direction to correct it, and pressed the brakes, but it was too late. I collided with a car in the adjacent lane, and the car later turned about 180 degrees and stopped! The left side airbags in the front and back all deployed! However, I were not injured. I got out of the car, immediately called the police, and contacted the owner of the collided vehicle. Later, the police arrived to document the incident. I believe it was a malfunction of the Tesla that caused the accident! I did not make a left turn manually! It was in normal driving mode. What component or system failed or malfunctioned, and is it available for inspection upon request? I have no idea, should check Tesla's driving records and the recorded video from the incident. Has the problem been reproduced or confirmed by a dealer or independent service center? No. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives, or others? No. Were there any warning lamps, messages, or other symptoms of the problem p