The warning tones for leaving my headlights on, and keys left in ignition quit working years ago. Not fun to come back to the truck only to find a dead battery so finally decided to try and fix it. After a number of information searches came across a recommendation to replace the door switch or at least swap it with the one from the passenger side. Did that an magically the warning tones started working again! It appears the control module (or whatever it is) couldn't tell when the door was open. Anyway, a potential and inexpensive fix that might save you from being stranded at some time.