Toyota Repair: Toyota 4runner key reminder and remote lock, toyota 4runner, door switches

Question
I have a 97 4runner. A few days ago I noticed that when I opened the door to exit the vehicle, the dinging noise occurred - like I left my lights on or left the keys in (I'm not sure if there are different sounds for those).  Neither was the case.  I also found that my remote lock didn't work either.  I'm guessing the two are related.  Perhaps they have a control programmed in so that you can't lock the doors with the keys in the ignition?  In any event, is this a key switch problem, or something else? Any idea how I can isolate it?  I can live with the dinging noise, but I really need my remote locking (my keylocks aren't working).
Thanks in advance for your time and assistance!
Dale

Answer
As long as the noise is there the doors can't be locked with the remote because the body ECU sees the key as being still in the ignition, this would also make it not possible to lock with the manual door switch either. There are couple of possibilities, one is that the ignition switch has a problem, the body control ECU is causing this or one of the door switches is bad, see if the door ajar indicator light on the dash stays on or the dome light stays on after all the doors are closed.