[xPosTech]

I don't know what year Seville you have but try this: lock and unlock with the key both front doors, and the trunk (and maybe the glovebox?) several times. You have either a bad sensor or corroded connections on a VATS sampled sensor. The locking and unlocking might wipe corrosion off a flaky switch.

Corrosion seems more likely than a "dead" sensor. Do all the door open/ajar switches work correctly (IE turn on interior lights)? Does the trunk light work correctly? The underhood light (parking lights on)?

I don't know if the ATS will set if a door is left open. I'll try my Eldo later and get back if no one comes up with a solution. Most alarms sense a change in levels rather than a truth table to set a safe condition but ours may use both. I've never checked mine but I will regardless. Would be good to know.

Ted