Rain sensing wipe issue

[Tizzy]

2019 2500 Laramie factory rain sensing wiper.
Set to “on” in uconnect and stalks switch set to “intermittent”. Upon cold start up I get a single wipe and as I drive an occasional, random single wipe when no rain is present.
Oddly, when it does rain, the wipers respond automatically working as intended.
I first replaced the gelpack but the same symptoms remain.
Then, I replaced the sensor that came with a gelpack installed but the same symptoms remain.
I tried a recalibrate with AlphaOBD. But I get a ECU error. I’ve read others say that the calibrate doesn’t work anyway.
I haven’t dug through Alpha to see if any settings need adjusting.
Any ideas? Any help would be greatly appreciated!!!

 

[Gondul]

Mine also does the random wipe... with no answer on how to 'fix' I finally turned it off.

 

[Will_T]

Mine also does the random wipe... with no answer on how to 'fix' I finally turned it off.

I had noticed mine also randomly wiped across a dry windshield, so I also turned mine off. Have not missed it. In fact, until I saw this thread, I had forgotten it was even a feature.

 

[Tizzy]

The three settings that others have set to “yes” when adding this option to trucks it didn’t come factory on are
Vehicle config2 rain sensor present
Cust set menu1 rain sensing wipers
LIN & Misc Humidity Rain Light sensor present
I have verified those are all set to “yes” in mine.

A new one I need to check is…
CBC config I/O & feat humidity long sensor (should be “yes”).

 

[Tizzy]

Anyone know what these mean?
Vehconfig 8: Rain Light sensor windshield 880nm transmission 0-15
Vehconfig 8: Rain Light sensor windshield 550nm transmission 0-15

 

[johnnyroastbeef]

@Tizzy i am purely offering a guess here...but could this be the setting where the rain sensor senses rain and turns on the headlights?
(maybe that's not even what you're asking?)

 

[Tizzy]

I wasn’t aware of that function. That may, indeed be what those settings are for.
Still haven’t figured out my issue. Sounds fairly common though.

 

[arx237]

Anyone know what these mean?
Vehconfig 8: Rain Light sensor windshield 880nm transmission 0-15
Vehconfig 8: Rain Light sensor windshield 550nm transmission 0-15

Looks like settings for the wavelength sensitivity of the IR sensors. These rain sensors as far as I know work by reflecting IR off the windscreen and measuring the return to determine how rainy it is.

Mine is currently set to
880nm = 4.00
550nm = 11.00

I do not know which direction increases or decreases sensitivity. My guess would be higher is more sensitive but I got a 50/50 chance of that being right. So maybe taking this to either 0 or 15 then monitoring the results may allow you to figure out settings that deaden up the sensor enough to help eliminate the false positives.

 

[Tizzy]

Excellent! I will check into that later.
Thank you!

 

[arx237]

I should clarify those are factory settings. I have not and likely will not fiddle with this system as it is working well for me so far.

 

[Tizzy]

Looks like settings for the wavelength sensitivity of the IR sensors. These rain sensors as far as I know work by reflecting IR off the windscreen and measuring the return to determine how rainy it is.

Mine is currently set to
880nm = 4.00
550nm = 11.00

I do not know which direction increases or decreases sensitivity. My guess would be higher is more sensitive but I got a 50/50 chance of that being right. So maybe taking this to either 0 or 15 then monitoring the results may allow you to figure out settings that deaden up the sensor enough to help eliminate the false positives.

That’s where mine were set.
Still exhibits same symptoms.
I had read somewhere the auto wiper is somehow tied in to the “auto” climate system. I’ll have to verify that and possibly investigate. It’s quite boggling.

 

[arx237]

Did you try adjusting the numbers and seeing if anything happens?

 

[Tizzy]

I’ll do that tomorrow. I kinda gave up on it for the last year. lol