Unfortunately, all the new tech seems to rely on cameras.
Tesla is the
only automaker using
cameras to (attempt to) detect rain on the windshield.
All other automakers (and older Teslas) use optical rain sensors that work by shining infrared light at a 45° angle on the inside of the glass and measuring the amount of light reflected back. Water droplets on the outside of the windshield will disperse some of the light resulting in less of it being reflected back. This type of rain sensor has been around for decades and works very well. It only adds a few dollars to the cost of the vehicle, but Tesla is
obsessed with (prematurely) eliminating sensors in favor of using the existing cameras...
to a fault. I'm good with eliminating sensors, but
not before they are needed for proper operation.
The problem with using the windshield-mounted cameras to detect rain is that they are inches from the windshield and focused on what is in
front of the vehicle - not on the
surface of the windshield. Because of the focus distance of the cameras and their proximity to the windshield, they are physically unable to see raindrops in sharp focus...because physics. If the cameras focused on the windshield, they would be great at detecting rain, but unable to detect more critical objects such as other vehicles, pedestrians, lane markings, etc.
I am not convinced that Tesla will ever be able to develop consistent and effective automatic wiper operation (or full self-driving) with the existing hardware. The best I can hope for is the ability to turn the wipers off
and have them remain off even when using TACC+ and just operate them manually the way I did for decades. I'm not being pessimistic - just realistic.
With that said, the auto wipers in my 2023 Model Y with HW3 worked nearly as well as the auto wipers in my other vehicles with dedicated rain sensors from the time I took delivery in April 2023 until February 2024 after updating from 2023.44.30.8 to 2024.2.2.1. Since then, my auto wipers have gone from acceptable to unusable. Updating to 2024.2.7 made them even worse. The cameras and windshield are perfectly clear, yet the wipers will randomly activate in dry conditions night and day. They will usually turn on when it is raining, but will randomly, haphazardly, and inappropriately switch between intermittent, low, and high without a corresponding change to the amount of water on the windshield.
If I could roll back to the auto wiper operation I experienced ending with 2023.44.30.8, I'd be happy.