Rain sensitive wipers

djkenn · December 29, 2016

My IS250 has rain sensitive wipers and I am struggling with them. There is an adjustment on the wiper column with five settings, are these supposed to be the sensitivity (which I presume means the density of rain landing on the sensor)? Which setting is least sensitive?

johnatg · December 29, 2016

See p135 of the owner's manual (section on rain-sensing windshield wipers). It describes operation in each of 7 switch positions. It should be available on line somewhere if you don't have one.

rayaans · December 30, 2016

The wiper stalk should click down.the highest setting is single wipe and this one will click downwards automatically to off settinf, next one down is Auto and the rest are intermittent wipe settings of different speed.

There is a wheel on the same stalk which adjusts sensitivity. Just move it up and down, the mother upward setting is highest sensitivity

djkenn · December 31, 2016

Thanks. I had not been able to work out how much the sensitivity varied between most and least sensitive and was wondering if something was amiss.

To be honest I have my doubts about rain sensing wipers generally. I get that if you were on a motorway and was caught by a lorry hitting a big puddle or similar that they are useful, otherwise I would rather have an intermittent option with a choice of variation between the wipes, like my old BMW 5 series.

J Henderson · December 31, 2016

Not the biggest fan of them myself. They are hopeless in light drizzle and misty conditions.

Also, it's probably best to leave them OFF when you park up at this time of year to prevent them trying to operate when your screen and wipers are frozen.

NemesisUK · December 31, 2016

I've never understood why manufactures don't reset the Auto-wiper function when the IGN is cycled? Would prevent inadvertent operation on dry or frozen screens..

djkenn · December 31, 2016

I had read that one of the fastest ways to scratch a windscreen was ice on the screen and using the wipers.. best to use de icer or warm water, or wait for the demister to do its work. Yet you see so many folk driving around peering through a tiny hole in the ice on their windscreen, rubbing at the inside of the glass with a cloth, when a bit of patience is what's required.

is200 Newbie · December 31, 2016

I was always told to use cold water to run over the screen as and shock to the glass from doing it with warm or hot water could make any stone chip cracks worse or further extend any actual cracks.

.

cruisermark · December 31, 2016

I have them on my 430 aswell - I leave them in auto with sensitivity on max - 99% of the time they work fine apart from a misty foggy morning when the come on constantly. I think thy work very well

ColinBarber · December 31, 2016

They worked very well on my old RX400h, and they are completely rubbish on my IS300h.

rayaans · January 6, 2017

Work fine on all Lexus vehicles I've driven. The only issue is that the RX doesn't wipe if there's water already on the screen whereas the IS does.

February 11, 2017

How do you know if the rain sensor is not working as I can't seem to operate my mine on my 2006 is250

djkenn · February 12, 2017

I find with mine it's very variable how much water is needed on the screen to get them to start. I'd throw a bucket of water on the windscreen then jump in and start the engine. I did read on the forum that if the rain sensor gets dirty the rain sensor function will stop. I think the manual shows the sensor location.

Shahpor · February 12, 2017

The rain sensor is located next to the rear view mirror, at the top of the windscreen.

Give it a clean and then throw some water on it. If the wipers don't come on, then there is your problem.

Linas.P · February 12, 2017

2 hours ago, Shahpor said:

The rain sensor is located next to the rear view mirror, at the top of the windscreen.

Give it a clean and then throw some water on it. If the wipers don't come on, then there is your problem.

As well, when sensitivity is at highers setting, lightly tapping sensor enclosure should trigger the wipers, so you can check if anything is alive inside.

65mike · November 5, 2017

Hi all.

Mine tend to come on when it is damp and misty and stay on until they decide to switch off get fed up so turn them off before wearing the blades out.

I assume this is a normal thing to happen on the car

65mike

jumbojake · November 6, 2017

on my old avensis it was a bit flakey, but you could disconnect the rain sensor (behind the mirror), and the wiper would revert to a normal intermttent type.

So far on both our Lexus (IS and Rx) not had need to do this... when it starts paying up, I change the blades and all is good.

Linas.P · November 6, 2017

On 11/5/2017 at 7:11 PM, 65mike said:

Hi all.

Mine tend to come on when it is damp and misty and stay on until they decide to switch off get fed up so turn them off before wearing the blades out.

I assume this is a normal thing to happen on the car

65mike

My wipers are spot on except for very light rain (which sadly is most common type around London). So they either as you said.. stay too long, or wipe too fast or doesn't come on at all. Obviously, you can adjust sensitivity on the wipers stalk and sometimes it works just right, but if rain is light and intermittent I often just use "one-off" function (up 1) or set them to desired speed (down 2).