About two months ago I asked my manager if I could have my girlfriend ride in the delivery truck I drive for him for a few days because of personal reasons. He said that he couldn’t let me do that because it is a serious liability issue. I have a part time job that I go to after my main job and sometimes I give a coworker a ride to that part time job. She usually meets me at my work place and then we take my car to the other job. On Friday she got off the septa bus at the wrong stop which is around the corner from my work place. So at the end of my delivery route, because the whether was bad I picked her up in my delivery truck and drove her back to my work place, there was only a half an hour left in the day and she was just around the corner close to my work so I didn't think it was a big deal. When I got back to work my supervisor saw her and I in the truck. After I finished my work and ended my day, my supervisor came to me and said that it is unacceptable that I had her in my truck and gave me two days off with no pay.
I tried to explain that she was just around the corner and he yelled at me that he didn't care what the situation was, there is no excuse for it, we discussed this before and that is the end of it. He said that the circumstances aren't any of his concern; it’s not his business and he didn't care. He said that I am a professional and should know better, not to mention that we discussed it before. Is this legal? Can he yell at me and not even let me explain?
Thanks

What part of "No" did you not understand when you were previously told that she could not ride in the truck?

You violated company policy and, in many places, your deliberate violation would have had you out looking for a new job rather than merely be suspended for a few days.

About two months ago I asked my manager if I could have my girlfriend ride in the delivery truck I drive for him for a few days because of personal reasons. He said that he couldn’t let me do that because it is a serious liability issue. I have a part time job that I go to after my main job and sometimes I give a coworker a ride to that part time job. She usually meets me at my work place and then we take my car to the other job. On Friday she got off the septa bus at the wrong stop which is around the corner from my work place. So at the end of my delivery route, because the whether was bad I picked her up in my delivery truck and drove her back to my work place, there was only a half an hour left in the day and she was just around the corner close to my work so I didn't think it was a big deal. When I got back to work my supervisor saw her and I in the truck. After I finished my work and ended my day, my supervisor came to me and said that it is unacceptable that I had her in my truck and gave me two days off with no pay.
I tried to explain that she was just around the corner and he yelled at me that he didn't care what the situation was, there is no excuse for it, we discussed this before and that is the end of it. He said that the circumstances aren't any of his concern; it’s not his business and he didn't care. He said that I am a professional and should know better, not to mention that we discussed it before. Is this legal? Can he yell at me and not even let me explain?
Thanks

And, yes he can. It is not illegal to yell at you and he is under NO obligation to listen to anything you had to say.

You bet it is legal. What is there to explain? You were told no, and you did it anyway. That's all he needs to know.