pulling and pressing real hard. I've had this problem, too. I fucking hate electronic parking brakes btw. In my current vehicle, it doesn't always engage for some reason, so if you're not super careful to feel for the engagement and make sure the light comes on, you get out and it starts to roll. I've entered a moving vehicle for that reason. Oh and the reason this happens is as long as you're sitting in it it apparently engages a hill holder. When it detects you've gotten out it lets off. Or something like that. I dunno it doesn't roll until you get out.