Automatic Wiper Operation

[Morrishey]

I've just got my Auris, complete with auto-rain-sensing wipers.

One question that came to mind while we were working out how everything worked, hopefully someone here will be able to answer.

What activates the rain-sensor? Is it the presence of something obscuring the sensor, or the actual motion of rain hitting the screen near it? Reason I ask is that we were wondering what affect a frosted/snow covered windscreen would have. I don't want to turn the car on and have the wipers trying to operate while they are firmly stuck to the glass, which I can imagine happening if it's based on an obscured sensor. Should I be turning off the automatics until the screen has cleared as a matter of habit?

Thanks.

[OldSkoO1]

I dont know how it actually works but in my experience it only ever activates when something touches it whilst in operation, so a raindrop or snow flake.

The auto lights must just be a simple light sensor which i think is in the same unit.

With frost, it only ever activated itself when i left it on auto and i was cleaning the windscreen; when i scraped the ice off the screen over the sensor i got a bit of a surprise when the wipers started!

Now i just leave them off and when it starts raining just push the stick down 1 place and let them do their auto job. Turning off if it stops and if i remember.

[mbrennan29]

As previous poster said, it appears that they activate when movement is detected on the screen.

I leave mine on all the time and they never come on when the screen has been frosted, only activating when i have been clearing the screen and giving me the fright of my life!!.

[Johan007]

Money would have been more wisely spent by Toyota on a HUD making the car rather unique :P