My car dies after it starts up and the sciceriy light flashes when doing it, the key also gets stuck in the ignistion, i took it to gm and got a new key and had them figure out what was up with it. the key solved the shuting down right after starting so far as of a day since they worked on it, but the key still gets stuck in the ignition???? pleas help, i think it is an ignition cylender, or a sensor for the trans, the gm dealer says its a 350 dollar theft module???