My 99 rx300 developed this problem last winter. It fixed itself in warm weather. Then 2 weeks ago after I installed a new batterry It really got going . It randomly chimes as i'm driving, some times non-stop ! It even would lock itself when unattended, then set off the alarm when it registered a chime. (The nieghbors love me)
The car is no longer in waranty and I can't afford the dealer taking 3 days to fix it. I find find something on the web about a simular problem on the 470 but not the rx300. I studied pulling a fuse but it looks like that fuse supplies most of the dash. I tried disconnecting the battery for one minute, to reset ,but ..no luck.
HELP ME STOP THE RINGING, PLEASE!

JoeyZ

 

If it's the door open chime, then I'd check for a problem with one of the switches on each door that tells the car the door is closed.
When you're driving and it does this, do you get the light on the dashboard that tells you a door is open?

 

Not sure if resetting the ecu will work, but, 1 minute is not the time. Try 1/2 hour. You will loose all memory settings.

Salim
..five ..

 

The door open detection switch is part of the latch. Many things can cause this problem. There are updated /recalled ECU's for 99 models. Multiplex communication errors can only be reset by unplugging the driver's side window master switch. Try unplugging the switch and see if it helps.

You can get to this switch by removing the door panel. Once its off you will see a single wire in most cases as the second wire is the body ground. However in some cases, there are two wires. In any event you will see the wire(s) that plug directly onto the latch assembly. Sometimes the fix is just cleaning it up and lubing the connection. Some latch assemblies need to be removed for more cleaning. Usually it works again after its serviced. What is happening is that switch is stuck in the 'closed' position, it cannot tell when the door is open.

this fix was posted in another forum and i have edited it to hopefully help with your issue, goodluck

 

THANK YOU.... Can't wait to try this ..... JoeyZ

 

Yes the dash warning light flashes ... the light around the key falshes.... and if i didn't shut off the overheads.. it would look like a disco at night .... the door open sensors are in the Latches ? I am think it's the front passenger door. (I tell my wife that the car doesn't like her) Is there a wiring diagram on line for the doors ?
Thaanks for everyones help.
Joey Z

 

if you look at the door frame on your 99rx i am told there is no switch that tells the vehicle when the door is open and closed. Most cars have the switch somewhere on the frame. the 99rx senses the door opening and closing using a component in the door latch. it makes sense that over time it gets wet and dirty so as i posted earlier just cleaning and lubing and disconnecting the wire will reset it. if it doesnt at least you have an area to point to the dealer or repair person to get them going in the right direction.