Power door lock actuator. You need to have your dealer trouble shoot as to which one it is (driver or passenger). Since you have central locking and both locks are tied in to each other, they also "talk" to each other. So you need to have your dealer figure out which one it is. They run about 100.00 each. I hate dealers, but something like this your dealer will know what to look for. There's really no way to stop it but to remove either of the acutators, which will remove your power door locks and illuminated entry (yes, they're all tied together). Damn computerized door locks! Would be nice if it was just the switches and solenoids, but unfortunately, it's not.