# Intermittent (Rain-Sensor) Windshield Wipers erratic



## atlantanorth (Nov 7, 2006)

*Windshield Wipers seem eratic*

This is the first car I have had with rain sensing wipers. Personally I am not impressed. When raining, sometimes they wipe quickly many times and other times they wipe once and wait (all this on the lowest setting - thumb lever all way to left). Anyone noticing this type of behavor when it is raining? I wish it would let me control it more for a sledom wipe to a faster wipe.


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## Hotmoose (Aug 31, 2006)

*Re: Windshield Wipers seem eratic (atlantanorth)*

From my understanding of the owner manual, it will wipe faster with the speed your going. Mine wipe once in a while, when on a red light but wipe often when i'm on the highway. Hope this help....


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## WolfsburgerMitFries (Jul 4, 2005)

*Re: Windshield Wipers seem eratic (Hotmoose)*

I've been wondering about the wipers. I think I remember reading somewhere that the Eos has speed sensitive wipers, is that true?


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## gilesrulz (Nov 2, 2006)

*Re: Windshield Wipers seem eratic (atlantanorth)*

Yeah mine wipe like an crack addicted squirrel too. I guess the most annoying thing is that you can't turn off the rain sensing, and just have an intermittent/speed sensing function.
The wipers are rain sensing and speed sensing (in the sport and lux versions). I wish they had just picked one.


_Modified by gilesrulz at 8:56 AM 1-29-2007_


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## ialonso (Aug 26, 2006)

My Wife's Grand Cherokee also has Auto wipers.. rain sensitive, speed sensitive, etc etc... I cannot stand them. they are TOO sensitive. Even at the lowest setting, they wipe way too much.
The only VERY NICE feature they have, is that when yoiu get splashed by an oncomming truck, they go crazy, turn on warp speed, and restore your vision right away.
I was very happy with my car because it did NOT have the auto sensing wipers.. 
Maybe you guys can get the adjusted or something...


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## WolfsburgerMitFries (Jul 4, 2005)

*Re: (ialonso)*

Sounds like there needs to be more programming options available to the owner so the operation can be tailored to their individual preferences. Maybe something could be changed in the VAG-com programming.


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## gilesrulz (Nov 2, 2006)

*Re: (WolfsburgerMitFries)*

As far as I know there are only two vag-com settings for the rain sensor, and they correspond to different types of glass used in the windshield.


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## irbrenda (Oct 9, 2000)

I have the Auto Sensing wipers on my Touareg and they work the same way...one wipe at a red light and crazy when highway driving.
Um..one lesson I learned though the hard way. I can leave them in the Auto Sensing position at all times and if it starts to rain, they turn on by themselves.
A few months ago, I had to pull over on Rte 22W in NJ and wipe some dirt off the center of the windshield that was thrown from a truck in front of me.
I stood on the door frame of my Touareg, window cleaner in hand, leaned over to the center of the windshield and sprayed away. The wipers turned on automatically and poked me in the eye, causing corneal abrasion and a deep cut down the side of my face, not to say the pain I suffered!
My son had the best laugh but I leave the wipers in the Off position now.


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## owr084 (Nov 15, 2004)

*Re: (irbrenda)*


_Quote, originally posted by *irbrenda* »_
I stood on the door frame of my Touareg, window cleaner in hand, leaned over to the center of the windshield and sprayed away. The wipers turned on automatically and poked me in the eye, causing corneal abrasion and a deep cut down the side of my face, not to say the pain I suffered!
My son had the best laugh but I leave the wipers in the Off position now.

I'm sure your son was only thinking of this saying on a t-shirt: "It's only funny until someone gets hurt, then it's freakin' hilarious."


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## irbrenda (Oct 9, 2000)

*Re: (owr084)*

I'm sure he would have loved to put me on the YouTube!


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## PanEuropean (Nov 3, 2001)

*Re: Windshield Wipers seem eratic (atlantanorth)*


_Quote, originally posted by *atlantanorth* »_When raining, sometimes they wipe quickly many times and other times they wipe once and wait (all this on the lowest setting - thumb lever all way to left).

Michael:
We went through a bit of a learning curve with the rain-sensing wipers when the Phaeton first came out. What we learned was this:
*1)* The rain-sensor itself is very dependable, no-one has ever had one fail.
*2)* If there is a problem with the rain-sensor - meaning, an electronic problem - it will announce itself with a fault code. So, if there is no fault code, *do not* replace the rain-sensor!
*3)* Never, under any circumstances, attempt to remove the rain-sensor from its mounting on the top of the windshield. If it is removed, there is a great risk of introducing air bubbles between the forward face of the rain-sensor and the aft face of the windshield - this will really screw up rain-sensor operation.
*4)* If the windshield is replaced (for example, due to rock damage), the windshield installer needs to be very careful when removing the rain-sensor not to break it, and even more careful when re-installing it to make sure that no air bubbles are introduced.
Now, so far as what we as owners can do to ensure satisfactory performance of the rain-sensor:
*1)* Be aware that whether you ask for it (purchase it) or not, just about every automatic car wash in the world will spray a 'rinse agent' onto the car just before it goes into the drying cycle. This is the same as the rinse agent used in home dishwashers, it helps the water sheet up and flow off the vehicle.
*2)* Unfortunately, the rinse agent leaves a residue over the rain-sensor window, and this changes both the refractive index of the glass and the behaviour of water on the glass. Both of these changes confuse the rain-sensor.
*3)* The fix is simple: Clean the rain-sensor window area with a strong cleaner (e.g. isopropyl alcohol), or scrub it with a little bit of powdered household cleanser (e.g. Comet, Bon-Ami), then wash it with soap and water. There is more information about cleaning rain-sensor glass here: Detailed Instructions - Operation of the Windshield Wiper & Washer System.
The bottom line is that you must keep the glass over the rain-sensor absolutely clean and free of any chemical film, wax, rinse agent, etc. if you want to have consistent operation of the rain-sensor.
Michael


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## jgermuga (Jan 11, 2007)

We have this feature on our MDX and it works flawlessly. I like not having to futz with the wipers when the rainfall goes from downpour to mist to downpour, etc. Especially that greaaapppgh sound when the wipers hit a window that is dry. Drives me nuts!! And I would have to think it reduces the lifespan of both a crystal clear windsheild, and the wipers!!
Anyway, I was really looking forward to this feature on the VW. I'd have to say that although the Acura does a better job, I still think the VW feature works well enough that I will choose to use it rather than than turn it off.


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## mark_d_drake (Aug 17, 2006)

*Re: (jgermuga)*

Hey MDX and EOS in the house.. Is this a trend... Which year MDX got the automatic wipers, our (2001 : First year model ) doesn't .


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## jgermuga (Jan 11, 2007)

Not sure but ours is a 2005. Great vehicle. 0 problems.
I am eying the new model. Looks very nice and really steps up the features. Very well thought out cockpit, a best in class sound system, more HP and a state of the art traction control system.
Downside, the MSRP went up by almost 5k.
Will be interesting to see how well it fares. I definitely like the German car handling and ride for my "fun" car, but I'd pick the new MDX over a BMW X5 or a Mercedes M class any day.


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## mark_d_drake (Aug 17, 2006)

*Re: (jgermuga)*

We're taking the other track, given that the MDX is primary used for hauling kids and dog to Tahoe, or at the weekends we're intending keeping this one for as long as possible and getting a smaller commute car to take the daily wear and tear of her.. Now if only VW would bring the Tdi Polo over here...


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## jaminphoto (Feb 13, 2007)

*rain sensor*

Anyone know does the sensor actually works? And how are your experience with it?
It was raining the whole day today. On the way to work it worked very well, I never have to adjust the wiper eventhough the rain was varied from hard to drizzle.
But on my lunch break it was all over the place. At one point it went beserk and went full wipe eventhough it was only drizlling. 
All the time it always set to the least sensitive setting(most left).
This is my first car with rain sensor. I'm curious what can affect the sensor.


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## Theresias (Feb 11, 2004)

*Re: (mark_d_drake)*

For those of you which have problems with the sensor, there are different versions out there and VW also changed the supplier shortly. Your dealer can easily check which sensor is installed by using his diagnostic tool.
For those of you who want to check themselves, a problematic one was 1K0-955-559-AE (made by Bosch), the new and IMHO better one is 1K0-955-559-AB (made by TRW).
You can determine if you already have the 1K0-955-559-AB by checking the sensor pattern, this is how it should look:


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## ehdg eos (Sep 9, 2006)

*Re: (Theresias)*

If anything like on my Passat they are both speed senseitive as well as rain senseative. The heavier the rain the quicker they work the slower the rainfall the slower/more time between sweeps across the windshield the wipers make.


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## PanEuropean (Nov 3, 2001)

*Re: rain sensor (jaminphoto)*


_Quote, originally posted by *jaminphoto* »_Anyone know does the sensor actually works? 
...I'm curious what can affect the sensor.

I think it measures differences in light refraction. I do know that it is very sensitive to any film of chemicals on the glass - for example, the rinse agent that most automatic car washes spray on the car before the car goes through the drying blowers really screws the rainsensor up.
If the wiper blade is damaged (or, the part of the blade that passes over the rainsensor is damaged, anyway), it will not work well.
It's a good system, but it does require that you pay attention to keeping the glass over the rainsensor window perfectly clean. In practice, this means rubbing the glass in that spot with a wet facecloth that has some household cleanser on it about once a month, to remove chemical film and other stuff that has dried in place and is not easily water soluble.
There were a lot of squawks about it when the Phaetons first came out (every Phaeton has one), but once all of us figured out the cleaning routine - wet facecloth and powdered household cleanser - the reports of problems disappeared. FWIW, I don't think anyone has ever encountered a 'defective' rainsensor... it's one of those parts that just never breaks - so, if you are having problems with it, first clean the glass, then keep on cleaning the glass until it works well. Honest.
Michael


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## gilesrulz (Nov 2, 2006)

*Re: rain sensor (PanEuropean)*

To be honest, if you have to keep the area that clean for it to work properly, I'd call all of them defective. I mean if you have to do more work to get a 'convenience' feature to actually do it's job than you would if you didn't have the same feature, I'd say that was a pretty serious defect.


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## PanEuropean (Nov 3, 2001)

*Re: rain sensor (gilesrulz)*

It's a problem that is unique to the chemicals used in automatic car washes in North America - specifically, the rinse agent.
If you never take the car through an automatic car wash, it is unlikely you will need to clean the rain-sensor glass very often.
Michael


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## sydeos (Dec 30, 2006)

Have had auto wipers via a rain sensor on my BMW for 3 years. Works as advertised and I haven't had to pay any special attention to the sensor area on the windscreen. However I don't use automatic car washes at all.
The BMW system switches to a sleep mode whenever the ignition is switched off and must be reactivated each time you want to go to an auto mode. This eliminates the above mentioned problems with inadvertent operation. This does however mean that you only have auto wipers after you have asked for them to operate.


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## PanEuropean (Nov 3, 2001)

*Re: (sydeos)*

Same strategy on a Phaeton (intermittent wiping has to be re-invoked every drive cycle, it won't persist across start cycles). On the Phaeton, all you need to do to re-activate intermittent wiping after the car has been turned off is to change the setting on the dial by one notch, then change it back to where you had it before.
I'm not sure if an Eos follows the same operating strategy or not - perhaps you might have to move the stalk to a different position (e.g. off or continuous wiping), then back to intermittent to re-activate the system.
This lack of persistence across start cycles is very deliberate - if the car was started when there was ice or snow on the windshield, and the intermittent wipers suddenly became active, the mechanics of the wiper system could be damaged.
Michael


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## PanEuropean (Nov 3, 2001)

*Re: (PanEuropean)*

Related post, might be of interest: TB: Customer States Windshield Wipers, Streak or Smear (Includes TB 92 06 04).
Michael


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## oab97 (Feb 18, 2007)

*Re: (PanEuropean)*

So will putting something like Rain-X on the windshield mess up the auto-wiper sensing and cause it to go nuts? I'm a big fan of Rain-X, it would be a shame not to be able to use it on the Eos.


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## neweosowner (Nov 25, 2006)

*Re: (PanEuropean)*

The Eos does not require re-activation of intermittent wiping. You set the stalk to Position 1, and it is ready for rain-sensing operation. This is not disabled by shutting the vehicle off.
I suspect that improvements in the sensors have encouraged VW to allow the system to be active at ignition (only because they've changed the behaviour from previous VW models). I've never seen the wipers engage at ignition with snow on the windshield, but I've only had that situation three times so it's far from definitive.


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## PanEuropean (Nov 3, 2001)

*Re: (oab97)*


_Quote, originally posted by *oab97* »_So will putting something like Rain-X on the windshield mess up the auto-wiper sensing and cause it to go nuts?

No. I use Rain-X on my Phaeton, and the intermittent wipers work just great with it. However, when I have to clean the windshield with Comet Cleanser every 3 months or so to get all the car wash chemicals off (yes, I use auto car washes - such is life), the Comet scrubs off the Rain-X too, so I have to reapply it.

_Quote, originally posted by *Arlynn* »_Eos does not require re-activation of intermittent wiping. You set the stalk to Position 1, and it is ready for rain-sensing operation. This is not disabled by shutting the vehicle off.

I just want to double-check to make sure we are talking about the same thing - are you talking about rain-sensing wipers, or the conventional intermittent wipers? Do you have a rain-sensor on your car? There are two possible configurations in NAR - conventional 4 position intermittent, and rainsensor.
Michael


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## Theresias (Feb 11, 2004)

*Re: (PanEuropean)*

In MK5 based models, which means the EOS too, have the additional 4 position switch too. If a rain sensor is installed this switch adjusts the sensor sensitivity not the conventional wiper speed.
Did any of you double check the sensor pattern yet to check which sensor he has?


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## vweosdriver (Oct 30, 2006)

*Re: (neweosowner)*

One reason given for BMW's wipers operation is to keep them from operating in a car wash, when the driver forgets they were in automatic mode, and being damaged.


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## _Rick_V_ (Jan 21, 2007)

*Re: Windshield Wipers seem eratic (atlantanorth)*

My previous car, a Lincoln LS, had rain-sensing wipers. As a feature, I thought it was going to be the coolest thing since sliced bread... That is until the first rain.
It was one of those spring rains where it would go from a steady rainfall to a very slight mist. It seemed like during the very slight mist, the wipers would go absolutely nuts-- running full speed as if it was in a panic, "Oh no!!! WATER!!! I'm melting!!" Then, when the rain would pick up, it would essentially say, "eh, so what?!" and my visibility would go to zero waiting for the automatic to kick in. Fortunately, on the Lincoln, I could turn the system off altogether and had a nice five-step intermittent settings. I ended up never using automatic again. Reflecting back, I bet Michaels suggestion of cleaning the rain-sensing area probably would've cured it.
On the Eos, during my first rain, the wipers worked so perfectly that I thought the Eos was working the same way-- that I had selected "intermittent" and that I had yet to turn on the Automatic. (it was just after delivery, so the wiper area was top-notch clean).
So, once again, I learned something new from this forum-- keep the sensing area clean. Thanks guys!
-Rick


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## neweosowner (Nov 25, 2006)

*Re: (PanEuropean)*


_Quote, originally posted by *PanEuropean* »_
I just want to double-check to make sure we are talking about the same thing - are you talking about rain-sensing wipers, or the conventional intermittent wipers? Do you have a rain-sensor on your car? There are two possible configurations in NAR - conventional 4 position intermittent, and rainsensor.
Michael

Sorry, I should have specified that in the sport package in Canada (which I own) you get the rain-sensing wipers, not the conventional intermittent wipers. Position 1 is for rain-sensing, with the supposed ability to adjust the sensitivity/speed of the rain-sensing wipers similar to the what was described in the PDF attachment in this thread. Again, it is enabled automatically at ignition and does not need to be enabled by the driver if the stalk is in the correct position.
I say "supposed ability" because I too find that the wipers do a lot of work when there is little or no water on the windshield - and its set in the "least sensitive" position. Given the amount of dirt and grime in any standing water on the road during an Edmonton winter, I almost expect this behaviour and will wait until Spring to determine how effective this rain sensor is.


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## sydeos (Dec 30, 2006)

*Re: (PanEuropean)*


_Quote, originally posted by *PanEuropean* »_
I just want to double-check to make sure we are talking about the same thing - are you talking about rain-sensing wipers, or the conventional intermittent wipers? Do you have a rain-sensor on your car? There are two possible configurations in NAR - conventional 4 position intermittent, and rain sensor.
Michael

Hey Michael
Having now received my car I can confirm that with the rain sensing wipers set in the auto position - rain sensor active - that this function remains active at all times and does not need to be reactivated after a start cycle unlike the BMW system.


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## SoCalMan (May 21, 2007)

*Re: Windshield Wipers seem eratic (atlantanorth)*

Much of So. Cal finally received some rain yesterday, so it was the first time
I was able to use the rain sensing wiper.
Happy to report that for a techno gizmo, they worked pretty darn well. 
http://****************.com/smile/emthup.gif


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## liquid stereo (Feb 26, 2003)

*Fantastic*

I hated them at first but they're working much better now. They used to turn like crazy with a little rain but now the speed is almost always appropriate. The one area in which they're too aggressive is when there is a light but constant mist. Under those conditions, they're a bit too aggressive.
Its a great system.

_Quote, originally posted by *SoCalMan* »_Much of So. Cal finally received some rain yesterday, so it was the first time
I was able to use the rain sensing wiper.
Happy to report that for a techno gizmo, they worked pretty darn well. 
http://****************.com/smile/emthup.gif


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## kghia (Nov 16, 2006)

*Re: (oab97)*


_Quote, originally posted by *oab97* »_So will putting something like Rain-X on the windshield mess up the auto-wiper sensing and cause it to go nuts? I'm a big fan of Rain-X, it would be a shame not to be able to use it on the Eos.

I don't have rain-sensing (really *light sensing*) Eos, but I can predict an issue with sensor-RainX combo -- RainX will make you _need less frequent wiping_. I would almost think that RainX over the sensor, *buffed off really well*, would make that portion shed the same as the rest.
The reason I say this is that I too _love RainX, and on my Eos (w/o rain sensor) it results in needing to use a lower speed on the wiper for any given rain_ (usual effect of RainX)
I don't think that the sensors will know to change.

_Quote, originally posted by *_Rick_V_* »_My previous car, a Lincoln LS, had rain-sensing wipers
--SNIP--
It was one of those spring rains where it would go from a steady rainfall to a very slight mist. It seemed like during the very slight mist, the wipers would go absolutely nuts-- running full speed as if it was in a panic, "Oh no!!! WATER!!! I'm melting!!" Then, when the rain would pick up, it would essentially say, "eh, so what?!" and my visibility would go to zero waiting for the automatic to kick in.

Mu guess is that this happens because the mist collects instead of rolling off, while the harder rain just sheets off. I think you have the general solution-- clean area over sensor so rain flows off. I can't help but think that a _good clear/well buffed_ application of RainX would help keep rain from staying there.
There _is_ a VAG-COM setting to change delay in the headlight washers, & the headlight wipers, and DRL %-of-full-- maybe one of the "unknown" bytes in the Central Electronics module is for a percentage factor for the intermittent settings?








_That certainly would be nice if an updated label file for VAG-COM shows a wiper speed setting!_ http://****************.com/smile/emthup.gif
It really makes sense that they would have set it there, given the other things they set.







(project for someone! -- test "unknown label file settings and submit to VAG-COM. hmm..)
William


_Modified by kghia at 8:28 PM 8-28-2007_


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## Tim Birney (Jun 2, 2003)

*Re: (Theresias)*

My 1K0 955 559 M
Works flawlessly
(Build Date 04/05, Jetta MKV TDI)


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