604 C63

I put them on low, rain sensing and they work just fine. But invariably I'll come off a light and they'll go nuts and start wiping to beat the band. They are on the turbo setting and the only thing that slows them down is turning them off and back on again.

WHat do I need to do?

jarjoug

I have the same thing happening, actually it always happens. They usually go crazy, wipe 10 times fast and go back to normal. I just turn them off and on.

George

elijah

Same thing happened with my X3. Sometimes it would just go nuts even though it was barely raining. Went straight to the dealership and they fixed it within minutes.
Head back to the dealership, they should fix the issue.

cyberorth

The rain sensing system gets confused. Normal for this car!

604 C63

how do you unconfuse it?

mr inkredibul

I laughed when I read this...I have no idea why?

604 C63

I know its not a real word....but you get what I mean

mr inkredibul

Totally! I want the answer too. I have to shut mine off a lot because its not raining and they are going crazy.

cptdaz

I think the better question is: where's the rain sensor located?

604 C63

Behind your rear view mirror.

ATL_MB

I have had 3 M-Bs with the rain sensing wipers - each year they are better than the last, so you can imagine how crappy my '04's wipers were.

The only thing that I have found that helps this is to keep the windshield absolutely spotless and the wiper blades should be regularly cleaned / wiped down. Even a very light layer of crud or dirt (even just a little rubber from the wipers after an hour or so of using them) seems to confuse the sensor into thinking the windshield is wet.

bluejae

i use the orange rain x windshield wiper fluid... helps me use the wipers a lot less often... so i just keep them off unless i really need them... sometimes even in heavy rain i don't need the wipers... and the wipers will also last longer since you're using them less

Shifter

are you leaving them on when its not raining? Because they are not designed to be. Turn on and leave alone when raining, then turn off when rain stops. The sun hitting the sensor at the right angle can fool the sensor.

cyberorth

OK I think this is sort of self explanatory.
The sensor thinks there is more rain than actually is and it speeds up the program; that's all.

604 C63

Nope. I RTFM and saw that they should only be on in the rain.

604 C63

Well, i understand the cause of it, but if you think how to reset it is self explanatory than you are a smarter man than I and I wish you'd share. I have had several cars with rain sensing wipers and none have done this.

604 C63

Once I figure this out I'll be sure to post it up.

Mort

Haha...I guess I have always just lived with it. Our 2005 C was terrible for uncontrolled high speed wiping but our 2008 R was much more controlled and better behaved and my C63 has given me very little problem. On either it seems it would not stop wiping at high speed once it started but I did wait it out a couple of times and eventually the speed reduced and things settled down. I used to put the wipers on slow continuous wiping to get the speed back under control and then back to intermittent if it was not heavy enough to warrant continuous operation. I suppose you could turn the wipers off for a few seconds and then back to intermittent to achieve the same results but that may impair visibility. I have also had them go straight back to high speed wiping and thus left them on slow continuous wiping for a while to keep things under control. I also give the windshield a shot or two of windshield washer to try to clean any dirt that may be on the windshield off and to break down any oils that may be smearing on the surface of the glass. I think the windshield may be getting a film build up on it in the dry with tar and oil from the road and this may be smearing around when the windshield gets damp. It will take a while for this oil smear to be washed off and that may confuse the rain sensor into thinking the rain is heavier than it actually is on the lower part of the windshield. A couple of times it seemed that the wipers went on to high speed operation while on intermittent setting when I gave the car a fair amount of throttle position. But that may have just been coincidence rather than a controlling parameter for intermittent wiper operation. If you do leave the wipers on intermittent all the time (my wife does) they will come on for no reason at the oddest times to remind you. Also bug guts and bird splat do a good job of confusing the rain sensor as well. A few times I had to get out and clean the dirt off the sensor to get it to operate in a reasonable manner. In the mean time slow continuous operation or off returns sanity to the day.

cyberorth

Sorry I misunderstood "unconfuse!!!"
I turn off and then on as a remedy, or just let it spaz out for a couple of seconds and it goes back to normal.
Annoying but harmless.
Chhers

bushburninc63

Never had a problem.

roadkillrob

Bumping an old one - anyone have any resolution to this - going to take mine in this week to have it checked, when I put them on the lowest rain sensing setting, they wipe slow a few times, then stop then might wipe slow one more time and then they just go on high and stay there, even if no rain is hitting the windshield, they will wipe until the windshield is so dry they will start to squeak and nothing short of turning them off stops them - have to just do manual push the button one wipe at a time for anything short of low.

7 or 8 cars with this technology over the past 10 years and this is by far the worst one, have to assume something is wrong - did have our new X5 be a bit crazy when we got it and took it in and they replaced the sensor and all went to normal, so hopefully they can fix it!

Jasonoff

Mine do the same sh¡t. Annoying AF

roadkillrob

I will report back

Jasonoff

Good luck, sh¡tty tech. I don't think there's a solution.

jmueller

Mine does this too. My cure / fix is to spray the windshield washer fluid for a second or two. Generally it wipes that away with two cycles of the wipers and then they stop.