I have had my 1999 RX300 since 2003. On very cold days that first winter, the open door sensor didn't notice the doors were closed. Once the car warmed up, everything seemed fine. However, the problem has gotten worse. The dash light and chime are continuously ringing, regardless of temp. This problem has caused the overhead light to stay on and drain the battery. Other associated problems are the key light flashes, the keyless entry doesn't lock ( senses door is still opened), auto headlights have also stayed on at times. The lock in the driver's door has been changed, but that hasn't helped.
I now keep the overhead light and auto headlights off. Has anyone had this problem? Any resolutions, please let me know.

 

The door lock mechanism has the electrical switch. In other vehicles it used be a push button in the door jamb.


First order of business will be to determine which door out of the five. You can be lucky or it might drive you crazy to figure out which one.

If it is truly weather related (temp) you may try your luck with a body shop as it could be fixed with the door adjustment. A sharp mechanic can flick the latch and figure it out. PLEASE don't do it yourself (if you feel you are not qualified) as it may freak you out .. you will not be able to close the door with the mechanism already tripped.

The problem could be intermittent switch and that would require replacing the locking mechanism.

Salim

 

or it could be an intermittant wire, breaking inside the insulation near the hinge points.