Since you have been able to get it to work at some point in the past, the first thing I would suggest is to make sure you are pushing the interface all the way into the socket. There have been cases where the interface isn't seated all the way and it has intermittent contact with some pins. If the interface receives anything over can, you should see CAN: OK in [Options] -> [Self Test]. Since the powertrain bus is directly on the DLC here, there should definitely be traffic if the wiring/contact is good.