My 2002 ES300 has an “Auto” position on the wipers. It does not have an intermittent position. It has Off,Auto,Low and High. The owners manual does not really say much about the Auto position. Only that it is rain sensing. Mine has never really worked well in that position. I pulled off the sensor by the inside rear view mirror. It had some sticky goop on the inside of the glass. It was a mess. I was hesitant to but I removed that adhesive goop. Now my Auto wiper position does not work at all. Before it was slow to start working and would then work too well and keep wiping after the windshield was dry. There is an adjustment ****. It never seemed to make any kind of difference.
I have seen some videos online about unplugging the sensor by the rear view mirror. That goal would be to make the Auto position in to more if an intermittent type feature. I tried that and wipers do not work on a delay at all. Only low and high.
how can I fix this? I would be happy with regular ole intermittent wipers if possible. Or if the rain sensing would work properly.
Thanks.

 

Hello,

Do you have an OEM windshield? Pulling something that is glued to a windshield is usually not as simple, unless someone messed with it before. Regardless, now that the sensor is gone, you may need to visit a windshield repair shop and get an advice on how repairable the problem is. They are not perfect, but usually not as bad as your description, hence the suspicion..

As for getting manual wipers, depends on how the Body ECU is wired, could be as simple as plugging in a new switch, to blowing half of the interior, only one way to find out..

Hope this helps and best of luck!

 

My Windshield is OEM as far as I know. It appears to be the original. It has a Lexus label. So is the issue possibly that the sensor is no longer stuck to the windshield? The sensor was not stuck to the gel pad when I took it off. That gel was brown and kind of dripping out from where it appeared to originally belong. I assume that is just from sun damage? Car has spent its entire life outside in the sun until recently. I am sure that spot in the glass takes a beating.

 

Rain Sensor is held on by "tape"
89944-33010
Install the new rain sensor tape.

1. Remove the used rain sensor tape from the wind-shield glass or rain sensor.
   
2. Stick the new rain sensor tape on the lens surface of the rain sensor indicated by the hatched line.
   

NOTE:
Make sure there is no dust or fingerprint on the sheet surface.

Install the rain sensor.

NOTE:
Check that the no old rain sensor tape remains on the windshield after removing the rain sensor. In case the tape remains, remove the tape.

Clean the glassface with a cloth, etc.

The rain sensing on mine is not always accurate as well.

 

Is there a way to “default” the auto wiper to work just like a regular intermittent wiper?

 

none that I am aware of

 

Looked a bit more into it, the Rain Sensors are more complex than they appear, they are not only detecting the light, but also the vibration. More than that, for it to work properly, there Must be no air gap between the glass and the sensor, it is similar to how the new phone screen compares to older PDA screens, which had a separate digitizer and a visible air gap between the glass and the LCD panel.

OEM sensor, besides a proper adhesive, also came with a clear, silicone like film over the sensor, which ensured a solid contact to the glass with no air bubbles, if you look at a factory mounted sensor, it looks almost as if it is a solid piece with the windshield. Said Film is precisely what comes in the box for the Part Number that fortitude listed earlier, and it is crucial for the proper operation of the sensor, so I would start there.

To answer the question about retrofitting Regular wipers, the setups for those is completely different, Auto system has a separate ECU to control the wipers, it won't be as simple as swapping the stalk in to change it, if doable at all. With that, the Owners Manual for your car states that it should change to the Regular functionality should the system encounter a fault, so it is strange that it stops working at all.

Having said that, the system does appear to have Intermittent functionality buried in there somewhere, and it may be something that could be implemented using Techstream software, or by visiting the Dealership in your area, depending on the place, they may even do it for free, if it is a thing that could be done. With that, getting the tape for the sensor and seeing where you end up with it may be an easier option, just ensure that both the Glass and the Sensor are Spotless before proceeding, and be careful not to scratch the latter.

[EDIT]: Below is a very good video I happened to stumble across explaining the function of the Rain Sensor.


Hope this helps and best of luck!