You talking about the anti theft? If the van is not recognizing the key you are using to start it. This is what it is supposed to do. When it dies is the pass2 light flashing? Has the battery been out of it for a couple of days? Or dead a couple of days? It sounds like a key issue. If the battery has been dead or out of the van a couple of days it needs to be reprogrammed by the owners manual it has a set of steps to go throgh to get it back so it will runn with the key. If it is the key that came with it. If it is a duplicate key then it is what is making it shut off. The key has a chip in it that the switch recognizes and if the chip isn't there or it has lost its programming it will do the shut off thing.