dead space 3 awakened dlc ps3 bug

Me and my friend are playing dead space 3 awakened co op dlc for the ps3 and in chapter 2 after we go down the ladder and open the door to the room filled with enemies near the tram. After we kill all the enemies, we wait for the tram to come and the doors to enter the tram never open? We stand there for several minutes pressing the x button and it just keeps saying waiting for partner. What do we do please help cause we are stuck on this part and can't continue.