RAIN SENSE WIPERS

[Larz]

My 2007 had the usual wipers and I loved the wide variety of speeds possible while in intermittent mode. This 2009 has the rainsense system and over-rides the intermittent settings by wiping super fast or wiping too soon regardless of the setting. On my Escalade, all you had to do was remove the little plastic cover from the windscreen and unplug the sensor wire to make the car revert back to standard intermittent. However, after doing the same thing to my M, it doesn't revert back to normal intermittent. No matter what setting I use for intermittent, it wipes once and doesn't repeat soI plugged the sensor back in and I'm wondering if anyone knows another way to bypass the rain sense nonsense.
I can't help but wonder what super-fast-medium--slow once-super fast-slow once-super fast-medium change-ups do to the motor every few minutes. Plus it drives me crazy, LOL.

[svard75]

Isn't that a sensor builtin to the windshield?

[TDot]

Yup, just unplug it I say. I would bet there is a connector right around the rearview mirror that you can unplug (either in that black thing or near the roof finish), or wire you can clip.

[Larz]

Isn't that a sensor builtin to the windshield?

The sensor has a little lens that can be seen from outside just to the left of the rear view mirror. is mounted against the inside of the windscreen.
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It has a plastic cover that pops off to reveal the actual sensor and the plug that powers it.
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I already unplugged it, just as I did with my Escalade, but instead of reverting back to regular intermittent control, it pretty much leaves you with OFF and ON for wiper control.

[svard75]

Read through the FSM. Determined that the BCM when detects a malfunction with the rain sensing wiper all intermittent modes act like LOW mode. I thought about putting a piece of electrical tape in front of the sensor on the inside, however removal of the sensor means you have to replace it, likely because of the method it's adhered to the glass. If you can slip a piece of black paper in front of the sensor wouldn't it act the same as constant intermittent?

[Larz]

First, Thank you for going to all the trouble you always go to just to help others. The mark of a true gentleman !
The sensor (as you know) is a one-piece unit that sits against the windscreen with a layer of what can only be described as a sticky, gooey layer of gel that forms a complete seal around the actual lens. According to the FSM, the lens emits an infrared beam that spreads through that gel and acts as a detector that somehow reacts to water on the outer surface of the windscreen. What a convoluted, complicated, waste of time and technology - just so we don't have to click the wiper bar down one notch?
I reckon your idea of blocking the sensor lens is a great one, however:
The only way to slide a piece of paper or any other barrier in front of the lens requires removal of the sensor from that gel and you are correct - if you pull the sensor away from that gel, you have to remove and replace a new gel layer before reinstalling the existing sensor. I found a source where I can buy two new gel layers (about $15 each). I could pull the sensor away from the existing gel, place a piece of something over the actual lens that blocks the infrared beam, install new gel, and reinstall the sensor. That might trick the BCM into thinking the sensor is fine, but there is no rain. Tha might allow me to use the intermittent wipers without them defaulting to ON. The only other option would be to have the dealer reprogram the BCM (if that's even possible) to ignore the sensor and act like the car does not have this worthless feature.
If blocking the sensor doesn't work, I reckon I will repeat the process with another new gel, reinstall the sensor without anything blocking the infrared beam, and just learn to live with the wipers going bonkers every few minutes and overriding the actual intermittent setting I choose.

[svard75]

hey Larz how about cutting the gel out from the top of the sensor and leave the rest as is. you'll have some room to slide something in there. make sure it's got a tab so you can remove if it doesn't work. is the gel just around the edges of the sensor?

[Larz]

The gel layer comes pre-shaped to fit the area surrounding area with a cutout for the sensor. The actual sensor is raised compared to the surface of the rest of the sensor piece, with a slight border around it, so the gel never covers the actual surface of the sensor itself. Im guessing the infrared beam travels past that border and into the gel somehow? Here is another supplier on Ebay that I found. This gives you a good idea of how the gel-adhesive layer fits.

http://www.ebay.com/itm/Auto-Rain-Senso ... 39&vxp=mtr

[svard75]

Righto so use just a very sharp blade and cut the gel on the top side along the window from end to end then cut it again close to the sensor again end to end and remove that piece of gel using tweezers so you are left with a slight gap to slide a blocking disk or whatever you can make that'll fit in there.

[Larz]

Thank You, that is my plan. I'll report back if that is successful, otherwise I will learn to live with this 'feature', LOL.

[tof]

Bumping this thread. Has ANYONE figured out ANY way to revert the rain-sensing wiper function to variable intermittent? And does the intermediate setting (slow to fast) have ANY impact on the way the rain sensing function works? Like maybe it is supposed to adjust the sensitivity? I can't see where it makes any difference in the usually inappropriate response of the rain sensing system.

[Larz]

I talked to a service rep at the dealer. He is the one who gets saddled with anything concerning the wind screen, rain sensors, rear view mirror, etc. He told me there is NO way to down grade to manual intermittent control. According to him, the stalk markings that look like the old adjustment for intermittent speed is now a 'sensitivity' setting to adjust how the wipers respond to the sensor. I leave mine set to the lowest setting and find the wipers go mad much less often.

[tof]

Thanks for the knowledge, Larz. I will try running them on the lowest setting.