DiscoJango

2012 GS350 f sport. Original lexus windscreen + rain sensor unit.

Problem is, it barely works, it can be pouring down, with the auto wiper sensitivity set to maximum, and around 80% of the time it doesnt work. There will be the odd day where it works as per normal, however the rest of the time, im having to manually run the wipers. Windscreen is clean as i wash the car regularly.

Are there any other settings or calibrations that can be run on these? My previous car (is350) worked 100% fine 100% of the time!

LexusGSboy

Hey DiscoJango

Did you look at this post (and the rest of the thread) #30 . I'm wondering if your two relays need to be replaced? I don't know a lot about it, I just remembered reading this a while back and was able to find it pretty quickly.

DiscoJango

Excellent, thanks for sharing that, ill give it a go and see how it works out

boostinsc

Anybody else have this issue when you spray the windshield the headlights washers auto cleans at the same time is it normal?

CAKETOWN

iTrader: (7)

That's normal.

One of the biggest tells with the wiper relays going bad are if the wipers stop half way on ur windshield while trying to cancel using them mid wipe, they should go back down to resting position.

LexusGSboy

There is a logic to how they're supposed to work. I tried to find the thread I was thinking of but couldn't. Found a few others that indicated that the headlight washers will activate when the lights are on and you activate to wash the windshield. Something also said it doesn't happen every time - something like every 5th time. I was wondering if they has some sort of tempurature sensor also since folks generally talk about them for clearing snow while driving.

Looks like the 450h has a button to activate just the headlight washers but that doesn't exist on the 350 if what I read in another post is correct.

CAKETOWN

iTrader: (7)

Depends on what the car came configured with, I got that wash headlight button in my car.

DiscoJango

In my previous car, the headlight washer would only work in conjunction with the windscreen wipers, if the headlights were on. And it would only work every third cycle. Some vehicles have a button to manually wash only the headlights, but once again, the headlights need to be on for this to work!

mcomer

Has the windshield been replaced? The prismatic lens of the rain sense sensor needs to
"see" the glass surface, if it is not aligned with the mask or is mounted incorrectly it may
not be able to detect the rain properly.

JDR76

You're correct for the refreshed models. The headlight washer works the first time you use the windshield washer with the headlights on, then every 5th time thereafter. No more sensors or logic than that.

As for the headlight washer switch, that was on all GS models (350 and 450h) equipped with the headlight washers before the refresh. I am not exactly sure how that one worked, but it was deleted for the 2016 refresh and the refreshed ones work as I described above.

LexusGSboy

Thanks for clarifying that JDR! With a couple of the responses I wasn't sure if maybe there was something else different about how and when you got the button vs just having it be part of the normal windshield washing process.

bob256k

I also would like a performance subform , just so I do not have to search for threads. I think as the 4GS platform ages and the price of used cars drops we will see more performance mods, even if minor.