Auto sensor wipers on yaris hybrid 2023

[postie459]

Hi Everyone,

Has anyone had problems with Yaris auto wipers, mine wont come on until screen is well saturated even though i have them on highest sensitivity, as vision is impaired i have to switch to low speed, is there a fix?

Alan

[flash22]

clean your windscreen for a start

[postie459]

Already done that.

[CPN]

Specifically the part where the sensor is. You know where that is, right?

[postie459]

Yes thoroughly cleaned the screen area. The wiper comes on after rain has drenched screen but then works intermittently, when the screen is clear is still carries on wiping although there is nothing on the screen. 

[CPN]

If the rain is not fast enough to constantly drench the screen, they will stay intermittent. That's how they are meant to work. I've driven into a rainstorm where initially, it is intermittent then as the rain increases it goes to slow speed and then in the heart of the storm and it is p***ing down hard, it only then goes to fast speed. The sensor is looking only at a very small part of the screen and it is near the top which means it is more likely to be driven off by the headwind you are driving into...

[Primus1]

I wonder if using a windscreen cleaner that beads water off amplifies the problem?

[CPN]

5 minutes ago, Primus1 said:

I wonder if using a windscreen cleaner that beads water off amplifies the problem?

Indeed. It probably would.

[postie459]

I have only just got the car so ill give it a couple of more rainy day tests, i use autoglym fast glass  so i dont think this beads, as this is my first post i  appreciate everyone's input thank you.

[Trewithy]

21 minutes ago, Primus1 said:

I wonder if using a windscreen cleaner that beads water off amplifies the problem?

My car has a ceramic coating and all the glass is treated as well.  The rain drops bead and blow off the screen if the wipers are not operating but the auto wipers work correctly and vary their speed according to the intensity of the rain.   

[Cyker]

The rain sensors don't detect how wet the screen is; The two types I know of use either light or percussive sensors to determine how often they need to wipe.

The percussive type just detect the impact of rain drops on the screen, while the other type uses a light sensor and an infrared beam shining on the windscreen - The idea is when it's dry the infrared gets reflected differently to when there is rain and that triggers the sensor.

I guess if theres any sort of coating that blocks infrared that might mess up the sensor...?

 

Edit: Also, is it an original Toyota windscreen? If it's been replaced it may be the sensor pod hasn't been mounted and/or calibrated properly. Also if condensation has gotten into it

[TonyHSD]

17 hours ago, postie459 said:

Yes thoroughly cleaned the screen area. The wiper comes on after rain has drenched screen but then works intermittently, when the screen is clear is still carries on wiping although there is nothing on the screen. 

This is typical for all Toyota cars and for the reasons experienced above. 
Don’t worry about it. Just enjoy your new car and use manual control of the wiper to correct their work when necessary, safety first. 👍

[flash22]

it's a light refractive sensor, no problem with fast glass, RTF and some wash/wax can cause issues,

 

warm/hot water and a few drops washing-up liquid - avoid the paint just clean the glass

otherwise, get the sensor recalibrated

[postie459]

Thanks for the advice much appreciated.

[anchorman]

1 hour ago, postie459 said:

Thanks for the advice much appreciated.

You’ve stumbled on one of the few features that really suck.  Denso are brilliant but they can’t do auto wipers.  Previously you could disconnect the sensor and it would revert to intermittent wipe.  On a Mazda (that also use Denso) you can opt for intermittent wipers.  If you disconnect the sensor or your car it will revert to intermittent but it will constantly put a warning on the dash - wiper fault, visit dealer 🙄

[Slartybartfast]

I could be lucky, but the "rain sensing" function works very well on my car.

Maybe they've made a hash of the system in more recent models? Or cheaped out in favour of other gimmicks?

[flash22]

it does seem very hit and miss if it works 80-100%, in some situations like rain and bright sunlight it does not cope that well

[Cyker]

Agreed; Sometimes mine works really well, and other times I have to change the sensitivity switch constantly or give up and override it.

Mildly annoying but not the end of the world; As anchs says It's a shame you can't just disable the auto-sensing completely and use the sensitivity switch to control the intermittent interval instead on the newer ones - That would have been my preference!