S40 2002 Volvo, for some unknown reason the doors lock for no explained reason as might be described in owners manual. For a almost a year thought this was figment of imagination. Second problem has occured. Open locked car, start engine, drive two city blocks, and the engine shuts down. Turning the key to engage starter to start car fails. Turning key a second time locks key out of start position. The car has been immobilized. The fuel pump was turned off while driving the vehicle. Inspecting the fuses, it's was found that the 20 AMP fuse for the ECM Immobilizer circuit has blown. Dealer could find no defects except for the fuse.