Do you have the factory-installed alarm system? If you do, and it's activated, it will run for a few seconds, then die. To reset it, use the key to unlock the door. If the switch in the door is disconnected or defective, try the other door.
If you do not have the factory alarm, the body computer can get a glitch or voltage spike and self-program itself and the engine computer into thinking it has the theft system. From then on they are expecting the disarm signal at startup, but it's never coming. The programming can not be undone. You must replace both the body and engine computers at the same time. If you only replace one as a test, it will learn the anti-theft programming from the other computer. If you find used ones in a salvage yard, they must both come from cars that did not have the factory anti-theft system.
caradiodoc
Mar 29, 2009 at 8:24 PM
