Vehicle does not start anyway, so I would think, What do I have to lose by trying? But before I try anything I would just make sure with a Mazda dealer that by VIN # tear tag, or Calibration #, that the used PCM I obtained is the correct part # before I waste any more time.I would also make sure the good battery has been fully trickle charged overnight and maybe have cables attached to it from a battery charger or off a idling car to keep battery from going flat.