Hey, I have a 99 RX300 and I am trying to figure out why the "door open" light in the dash doesn't always come on when I open the front doors. I don't see any visible door switches of any kind, are they some sort of magnet switch in the body and door?

The light usually comes on after about 30 seconds, but often it doesn't come on at all, occasionally it comes on right away like the back doors. For some reason this problem is only with the front two doors, the back doors always function properly. Maybe because they are used much less, but if it's a magnet sensor they shouldn't good bad, at least I would think.

So if anyone can tell me where the door switch is located. Any info is greatly appreciated. Thanks, Garrett.

 

Some one else can confirm, but Lexus uses the latch mechanism for door ajar or closed. If the problem is not in the wires or connectors, then it is in the mechanism and one has to replace the whole mechanical assembly.

Salim

 

So you are reffering to the lock mechanism, the whole actuator/lock assembly? Well if thats the case I will find out soon because I just ordered one because the lock has been having issues locking/unlocking. So maybe I'll knock out two birds with one stone, I guess I'll find out. Thanks, Garrett.

 

No the actuator is a different piece. I am referring to the mechanism that grabs the hook on the door jamb.

Salim

 

I don't understand what you mean by "grabs the hook on the door jamb"

 

I think he means the latch mechanism (Latch Assembly, Door; #69040-48020 (left), #69030-48020 (right)). It's described in the Repair manual (for my 2002 RX300) on pages BE-109-119.

 

When you swing the door close, one end has the hinge, the other other has the mechanism to grab on to the hook on the pillar. This assembly has the mechanical connection to the door handle (release) and the lock mechanism. The door lock actuator operated the lock via an electrical motor (solenoid). Door ajar/closed piece is an integral part of the above mentioned assembly. So if the door ajar switch is bad, you have to replace the whole assembly. Lock actuator is connected to this assembly, but performs a different function. [ie lock actuator will not affect the door ajar/indicator]

I am basing this on GS. It is likely that RX has the same mechanism ... so I was hoping some one would confirm or refute.

Salim

 

 

Door lock actuator has the door ajar switch. It is in the mechanism that hooks on to the U bolt in the door jamb.

Salim

 

 

 

 

I bet you were expecting a simple plunger switch that directly turns on the light. No such luck.

The RX300 driver and passenger front doors have door ECU's that communicate to the body ECU.
The body ECU then decides what to do.

If you want more info, try googling for
RX300 body electrical BE pdf
RX300 diagnostics DI pdf

 

Switch is only one piece of the puzzle. You have wires and connectors and modules. I would get ohm readings on the switch part-wires to determine what is wrong.

Salim