The rain sensor in my 2001 LS never worked since I got it 3 years ago. The wiper runs fine in intermittent mode.
Before I spend money on replacing rain sensor and gel pack, is there a way to test the sensor to see if it's bad? Mine is Lexus original windshield, so glass is not the issue. Or do I have to take it to dealer to test?

 

Is the sensor on securely? Maybe the glue used has melted?

Check this thread out: https://www.clublexus.com/forums/ls-...-ls-430-a.html

Apparently, the car handbook states that if the windshield gets hot that the rain sensor may malfunction and it will default to the intermittent mode.

 

I saw that thread and some people actually had bad sensor. That's why I asked, any way for me to check the sensor or do I have to take it to dealer?

 

I can't tell if mine is working either.

 

There is a lexus specific gel pad sensor for our windshields. I had to get mine corrected when I got new glass installed. They are pretty cheap - maybe just call an auto glass shop.

 

Answering my own question.
Finally found a troubleshooting guide by searching for the techstream error code and followed it. After detecting 12V+ voltage at the wire harness connecting to the rain sensor, I figured that the sensor is bad.
Turns out that the original part number 89941-50020 was replaced by an updated version 89941-50021, so I assume the previous one had an issue. Though ebay is full of the old part number, I waited until I found one with the new part number. Dealer part is expensive ($300), so didn't want to go there.
Plugged in the one from ebay and rain sensing wiper started working. So the ebay gamble was worth it.

 

How much did you pay for the ebay sensor? This way, we have some figures to go by. $300 at dealer VS $x on ebay.

 

Nice fix. Since mine works, I try not to touch it. When I first got the car I touched it and I think the wipers activated, which I found bizarre. And I hate the wire going into the headliner, Toyota coulda done better there and hidden it.

It's one of my favorite features on cars, of all time. The other is headlamps that swivel. 2 of our cars have both features. 3rd fav feature is HID headlamps (not led). 3 of our cars have it. Trying to think of a feature that all of our cars have...nothing comes to mind. 2 cars have RWD, another good feature.

 

$65 plus shipping, ~$73 total.