Insane auto wipers

[S90]

Car is due for 1st service soon so will take this up with stealer, but my auto wipers seem to have developed Tourettes. They will work fine then all of a sudden start going at full speed, even though the amount of rain is still light. Only way to stop is to turn off auto feature and back on.

[BarryUK]

I get that too, but then I've had it with a couple of BMW's I've had too. I think it's fairly normal from my experience.

[gaby]

Does this happen during the day, or while driving under streetlights?

[S90]

Mmmm, good question, seems to happen at night, and yes, under street lights

[Jimrod]

Had the same in the S90, seems much of the electronics are flaky - parking sensors a little slow to respond too, then when a motorbike overtakes in stationary traffic they go off in random spots where there's nothing within 6 feet for a few seconds. :|

[Lexman8]

I've found the auto wipers to be the worst I've had in any recent car. Sometimes they don't come on even when the screen is covered with droplets but other times they wipe almost continuously when there are very few droplets on the screen. I'm always having to adjust the sensitivity control.

[steladamo]

Originally Posted by Jimrod

Had the same in the S90, seems much of the electronics are flaky - parking sensors a little slow to respond too, then when a motorbike overtakes in stationary traffic they go off in random spots where there's nothing within 6 feet for a few seconds. :|

I experience exactly the same. Although I can see that the car has enough space to pass through, sensors goes red and bibs like crazy and then while waiting at traffic lights and bikes are passing by a sensor will go off after the bike has gone by

[apnicolle]

I’ve given up on auto wipers, not just on the current car but pretty much every car I’ve ever had them on. I keep them on auto when it’s not raining, just in case some random water jumps over the windscreen (which happened once on the M4 when a lorry on the other carriageway went through a huge puddle and splashed over to my dry lane) then I turn them on properly and use intermittent or normal manual settings when it’s raining.

[AB-UK]

No improvement on the Mk1's wipers it seems.

[enrm6]

I find the auto wiping system on my XC90 much improved over my V70.

I think (guess) the system is probably optical, and so if the droplets on the screen are relatively undistrurbed, I.e. drops and not running, the system cannot see them. When you have some wind that smears them they are then visible and the system works as intended. On the other hand if the wind is strong / you are travelling fast and the smears are pronounced, the system thinks it’s monsoon weather and kicks into overdrive. However, as I said at the top, the likelihood of either of these conditions is much less now with a presumably much more refined version of the tech that has come about in the 14 years between my cars.

I have not noticed an issue caused by the presence of streetlights or not, but it figures that the refraction of the very directional light through the raindrop may affect the system.