jm55

It seems that the rain sensing wipers on my car have a mind of their own. Sometimes they seem to work as expected and other times it is running the wipers full blast when there is only a light mist from the vehicles in front of me throwing up the water on the road. Dealer said he reprogramed it because they thought it was acting up for them too and said that took care of the problem, but it rained today and it is still the same. Anyone else having these kind of issues with their car or is it only mine? Any ideas? Is there any kind of sensitivity adjustment on these things. Could it be the wiper blades? Car is only a couple of months old. TIA.

glennbaz

No I don't think it's the wiper blades. You can easily test anything your dealer does right away by using a simple spray bottle on the windshield. Apply a fine mist to the upper center of the windshield with the car running and the wipers in auto mode. vary the spray amounts and see how the wipers react. Although on occassion my wipers would act up, 98% of the time they work fine. When they do act up generally turning them completely off then back on or turning off the car then turning it back on will correct the abnormality. In your case I think it's either a bad sensor or a bad control unit. Hope this helps.
Glenn

lkirchner

The wipers are a little sensitive. On my SL55 when the car sits in the direct sun the wipers will come on once when the car is started. On my wife's E55 they will come on whenever they feel like it especially when it is perfectly sunny. The explanation that the service advisor gave me was bordering on insanity. They work perfectly well in the rain however. I have learned to live with the sunny day situation.

jm55

Going to a different dealer tomorrow and see if they can find a problem. These things are just too erradic to not have something wrong. I'll post what I find out. Thanks for the tip on how to test.

GOODENUF

You have to wonder sometimes why service managers/reps say some of the things they do. Its like telling a BS story, the more times they say it the more they belive it.

StephenK

Good idea, don't accept incompentance at one dealership as the way it is. Can't wait to hear what they say at dealership number 2.

jm55

So far second dealer is saying that it works OK when the car is sitting still and are wondering if the rain sensors are now programmed in the 07 model to be sensitive to the speed of the car moving. They say they have calls into Germany to get more info. At least they didn't just give it back and say there is nothing wrong.

jm55

Dealer said the rain sensor was loosing it's calibration. They recalibrated it and it seemed to work ok, but have a new one coming next week as this one is not able to maintain it's calibartion for some reason.

Multiowner

I have the same problem. The wipers have a mind of their own. I have brought back to dealer 2x and now they say its needs to be ordered from Germany. I refuse to hear all the BS and will give them 10 days for part to arrive and I will be back for the repair.
Please keep me posted. The car is a 07 SL550 about 5 months old.

jm55

They installed the new part on mine and it is much better. A little too sensitive for my taste, but it does not go nuts any more when there is no water at all.

ToonArmy

This is a "feature", although a particularly annoying one. If the wipers were set to auto when the car was switched off, then they will always wipe once when the car is switched on. This always bites me when I drive in the rain, then enter an underground garage - the wipers stop, and so when I park I don't realize they're still switched on. Return in the evening, start up, and am greeted by the scrape of wipers on dry glass.

The explanation, I am told, but don't really believe, is to remind you that the wipers are on so you don't drive into a car wash with them on and destroy them.

I do also notice cases where the wipers wipe near-continuously with the barest wisp of moisture, and conversely stay off when big drops are splattering the windshield. Ah well, if they were more intelligent, they'd take over my job

Multiowner

Thanks for the reply. I hope to have my sensor changed in the coming week.
Wonder if this a known problem in the 2007 models.

Dans_SL

I had the same problem and the crazy service manager told me the wipers only act crazy here in America because it's been programmed to German sized raindrops Should I believe him? lol jk
Oh, and he told me (an easy solution) if it ever happens again on the highway, is to pull over, shut the engine, go outside the car with a towel and manually dry the windshield, then get back in, set the wipers to manual and start the car. simple lol jk
You know, Untested new Mercedes technology has too many bugs... What was wrong with the old simple way of doing things?... Think about it, who really needs automatic wipers anyway?

Multiowner

Had rain sensor replaced and it now works perfect. If anybody is having problems with MY 2007 I suggest the get it replaced. Be insistant!

SL2003driver

LMAO

Scotsman

Strange, mine's the exact opposite. My wipers are always on auto and if it's pouring when I jump in, they don't sweep at first even though the rain's running down. Other than that, they're fine.

StephenK

On my 01S500 the wipers will wipe once when you start the car, on the 06 SL600, they will not wipe once unless it is raining or the window is wet. I like the SL option better than how it works on the S-Class.