something is open. It could be any number of things including the hood or tailgate latch also. Mine had a bent pin on the connector to the alarm unit and was not making contact. It would, however, activate the locks and such. Since you are experiencing an open sensor as well as no operation to the locks, I would make sure your connector is in fully. Could have come loose with wheelin or shoving things under the seat. Unplug it, make sure all your pins look straight and shove it back in. Hope it works for ya.