What I don't understand is that an auto-sense system is not supposed to have an interval setting. It's supposed to auto-sense and set the interval automatically based on the rain rate. I really don't understand how the interval adjuster works with the auto-sensor, they seem counterintuitive.

 

I've had auto wipers on various cars for over 20 years. None are perfect, often needing minor adjustment. I'm giving these RX wipers a shot but I'm afraid I'll be reverting to manual mode, again. Doesn't rain much in Texas, so that's working in its favor.

 

The control on the stalk isn't an interval setting; it is a sensitivity setting.

So in my mind, a lower sensitivity setting to water on the sensor would result in less swipes per a given amount of rain.
Or, put another way, the windshield would need to be wetter for the wiper to work.

 

Lots of rain here on the west coast, I have the same experience with the rain sensing system, really hit and miss but mostly miss.
I would rather have no rain sensing but instead old school intermittent function.
Oddly enough when I drive my wife's 2024 UX the rain sensing system works really well.

 

OK, so if its a sensitivity setting - then for sure its software. The sensor on the windshield I imagine is putting out a signal that give the ratio of glass to water it "sees". So as long as the wipers work when turned on, that rain sensor is working. Some software must read the sensitivity setting of the stalk, match it up to the sensor density reading, to produce the wiper rate. That software is getting confused.

 

Got my car back from the dealership and unfortunately, they could not find a fix for the auto rain sensing wipers occasionally not working. They were able to replicate the issue. They confirmed there is nothing wrong with the parts themselves and it's very likely a software issue. They ended up filing a ticket with Lexus and even shared that case# with me. From what I was told, Lexus is researching this and are they were told by Lexus that they hope to have a fix by May. It sounds like this will be very likely a software fix. Ideally, I would have like them to have a concrete plan/timeline of the fix but looking on the bright side of things, this is some progress. I'm crossing my fingers and hoping they actually come through with a fix. Living in the PNW, where it rains frequently, it's pretty frustrating to use the intermittent option when I paid for the rain sensing wipers.

 

The "by May" thing is interesting. Maybe they plan a software update for the car in May. They won't issue a fix for just this, they are going to roll-up a bunch of changes into a new release, and hopefully this will be one of them, in addition to some other software/infotainment gaps that forum people here have been complaining about since the car was released.

 

@DCM8OR did you actually get yours fixed or are you speculating that replacing the wiper motor assembly is the fix? Do you have a case # I can share with my dealership? Thanks.

I'm asking because I got my car back from the dealership today and unfortunately, they could not find a fix for the auto rain sensing wipers occasionally not working. They were able to replicate the issue. They confirmed there is nothing wrong with the parts themselves and it's very likely a software issue. They ended up filing a ticket with Lexus and even shared that case# with me. From what I was told, Lexus is researching this and are they were told by Lexus that they hope to have a fix by May. It sounds like this will be very likely a software fix. Ideally, I would have like them to have a concrete plan/timeline of the fix but looking on the bright side of things, this is some progress. I'm crossing my fingers and hoping they actually come through with a fix. Living in the PNW, where it rains frequently, it's pretty frustrating to use the intermittent option when I paid for the rain sensing wipers.

 

@2023Rex350 no speculation, this is what Lexus New Zealand were told by Lexus Japan to do. The problem is definitely in the motor assembly as that had the programming in it. Tell you dealership to make contact with Japan. Good luck

 

The software is in the wiper motor? Sounds like a terrible high cost design, that would mean its a custom wiper motor assembly. Well now its even more important that we all get it changed under warranty, so its free.

 

I'm sure it's not, the software that controls it would be part of a body control module that activates that and maybe other things as well.

 

I can assure you that it is. I've had no issues since my was replaced with a revised software update in it. The only reason it would still have a problem after that is if the sensor on the front screen has damage or the gel pad that holds the sensor to the screen has lost adhesion so the sensor can't accurately detect image deflection. Easy way to test that is to say the wiper to auto and try to wiggle the sensor cover and give it a tap. This will activate the wipers if the gel pad is faulty. I had this issue too which was the first thing done when I had the issue.

 

Not custom, just extra bits added. When you look at it from a diagnostic/ technician perspective it streamlines repairs as there isn't extra wiring and modules in the system. It's either the sensor telling it to activate, or the receiver of that signal which is only in one place instead of at least two.

 

Since I live in the Pacific Northwest, where it rains/sprinkles frequently, getting this fixed is a big deal for me. I decided to take actions in my own hands rather than wait for a potential fix in May that the dealership told me. I went under the sensor and I just noticed that the gel pad wasn't completely sticking to the window. As soon as I fixed that, my rain sensing wipers was a lot more sensitive. I'll definitely need to do more road test before I can say that it fixed the issue. I'll make sure to update this thread once I have my final conclusion. Luckily for me we are expecting some more rain showers tonight before it sky clears out for a week or two. Crossing my fingers here!

 

Any updates on this? Planning to go to the dealer to see what their resolution is.