Rain Sensor- swapped sensor, same problem
Thread Starter
Newbie
Joined: Mar 2006
Posts: 16
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2006 cls500
Rain Sensor- swapped sensor, same problem
Hi
With the rain recently, I have been trying to fix my rain sensor. With a sensor plugged in, the wipers do not wipe intermittantly, instead they wipe at the same speed as setting 2. The car does this with 2 different sensors of the same model, so I doubt both sensors are faulty. I do have the blue glass bit that came stuck on the windshield, so I am puzzled to whats wrong.
With the sensor removed, I get intermittant wiping at one swipe every 5 seconds or so.
Can anyone think what is wrong with the wiper system?
I asked the stealership over the phone and they gave me a variety of answers, including saying that there may be a can-bus error? or that the setting is not set in star diagnosis. The car is a 2001 c240, and according to a vin decoder, it did come with a rain sensor, so unless the previous owner disabled the rain sensor, the rain sensor should be working.
any help/input is appreciated.
With the rain recently, I have been trying to fix my rain sensor. With a sensor plugged in, the wipers do not wipe intermittantly, instead they wipe at the same speed as setting 2. The car does this with 2 different sensors of the same model, so I doubt both sensors are faulty. I do have the blue glass bit that came stuck on the windshield, so I am puzzled to whats wrong.
With the sensor removed, I get intermittant wiping at one swipe every 5 seconds or so.
Can anyone think what is wrong with the wiper system?
I asked the stealership over the phone and they gave me a variety of answers, including saying that there may be a can-bus error? or that the setting is not set in star diagnosis. The car is a 2001 c240, and according to a vin decoder, it did come with a rain sensor, so unless the previous owner disabled the rain sensor, the rain sensor should be working.
any help/input is appreciated.
MBWorld Fanatic!
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From: Dar es Salaam, Tanzania
ML63 AMG
Hmmm, that's interesting. I'm not sure what the problem is -- I have a problem with my rain sensor too (or at least I think it's a problem). I keep it on the rain sensor mode (1 switch over), and when I turn off the car and turn it back on, it wipes once (although there is no rain). I don't know whether this is the standard or what, but the BMW remains on rain sensor and doesn't do that when you turn off and on the car.
Tee_Tz.
Tee_Tz.
Thread Starter
Newbie
Joined: Mar 2006
Posts: 16
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2006 cls500
the rain sensor is in front of the rear view mirror, inside a black plastic shell... with my car, the light sensor is seperate (2001) but in newer cars the sensors are intergrated into one. The rain sensor is a black rectagle cube like thing that snaps onto a blue piece of glass attached onto the windshield
Senior Member
Joined: Feb 2006
Posts: 411
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From: Florida
'04 C230K SS
check the windshield and make sure it's not chipped, scratched or dirty where the sensor meets it. Sometimes on the outside there might be a small piece of debris or dirt and might trigger it to wipe.
Hope this helps!!!
Hope this helps!!!
Junior Member
Joined: Jan 2007
Posts: 49
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From: Northern CA
'02 C230 Sport Coupe
Hmmm, that's interesting. I'm not sure what the problem is -- I have a problem with my rain sensor too (or at least I think it's a problem). I keep it on the rain sensor mode (1 switch over), and when I turn off the car and turn it back on, it wipes once (although there is no rain). I don't know whether this is the standard or what, but the BMW remains on rain sensor and doesn't do that when you turn off and on the car.
Tee_Tz.
Tee_Tz.
Super Moderator Alumni
Joined: May 2006
Posts: 4,539
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From: Southern Cal
a C32 AMG & S-Works Tarmac
I keep it on the rain sensor mode (1 switch over), and when I turn off the car and turn it back on, it wipes once (although there is no rain). I don't know whether this is the standard or what, but the BMW remains on rain sensor and doesn't do that when you turn off and on the car.
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MBWorld Fanatic!
Joined: Jan 2005
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From: Orange County
2005 C Wagon (No snickering please!)
The rain sensor consists of four infrared leds and four photo sensors. If the windshield is dry the light from the leds is reflected back to the photo sensors. This is interpeted by the front CAN, and it leaves the wipers off. If there is a droplet of water on the sensor it bends the light beam and allows it to escape. Since the beam is not reflected the CAN turns on the wiper. Anything on the windshield that can bend infrared light will run the wipers. Car polish, waxes, and Rain-X can absorb or bend the light and cause undesired operation of the wipers.
MB-Bob is right, clean the windshield well, use Bon Ami or your favorite cleaner to get everything off the glass.
If the LED's are burned out, the wipers will run. You can't see the light with the naked eye, but many video cameras, and a lot of digital still cameras can see the light from the windshield. See if they are on by pointing a camera at them at night.
MB-Bob is right, clean the windshield well, use Bon Ami or your favorite cleaner to get everything off the glass.
If the LED's are burned out, the wipers will run. You can't see the light with the naked eye, but many video cameras, and a lot of digital still cameras can see the light from the windshield. See if they are on by pointing a camera at them at night.
MBWorld Fanatic!
Joined: May 2003
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From: Houston, TX
2015 E250D
there is also the slight possibility the previous owner has it disabled in the car with star diagnose. If the windsheild was replaced with the incorrect model (blue glass vs. green glass) and the overhead control panel was not programmed accordingly, it may do the same as well. The rain sensor's 3 pin plug goes directly into the overhead control panel that houses the sunroof controls. The control panel has a few programmable strings regarding the rain sensor in it.
Super Member
Joined: Feb 2007
Posts: 857
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From: Downtown Columbus
w211 e500
Hmmm, that's interesting. I'm not sure what the problem is -- I have a problem with my rain sensor too (or at least I think it's a problem). I keep it on the rain sensor mode (1 switch over), and when I turn off the car and turn it back on, it wipes once (although there is no rain). I don't know whether this is the standard or what, but the BMW remains on rain sensor and doesn't do that when you turn off and on the car.
Tee_Tz.
Tee_Tz.
