Auto cruise control shutting off in sunlight

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Joined
Oct 5, 2023
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I searched for a thread about this but did not find one. I have been having issues with my ACC. When the sun is low in the sky and I am driving into the sun on cruise control the ACC will stop and give error messages. Once out of the sun no problems. And when the sun is high in the sky no problems. Has anyone experienced this before?
 
It seems like it used to be talked about more frequently when I first began driving this car in 2019, not so much lately. But you're right, the i3's ACC is strictly camera based, no radar, and as such has some problems with direct sunlight, dirty or speckled glass, or other challenging lighting conditions. One that regularly throws my car off at night is coming over a short hump of a freeway overpass and the camera gets an eyeful of a brightly lighted overhead signboard. If there's not another car in front of me for the system to reference, the signboard must confuse the heck out of it because it reliably kicks off every time. But yeah, low sun is the worst.
 
I searched for a thread about this but did not find one. I have been having issues with my ACC. When the sun is low in the sky and I am driving into the sun on cruise control the ACC will stop and give error messages. Once out of the sun no problems. And when the sun is high in the sky no problems. Has anyone experienced this before?
I've seen this too. First time I saw the error message it looked pretty dire compared to the actual seriousness of the situation. I initially thought the ACC was broken.
 
As a rough guess I have about one second after the sound of the disconnect Bong to regen bring applied – so about a second of "coast.'

It just enough time to get my foot onto the accelerator pedal before slowdown is triggered, but no time to spare.

I find it about right for attentive monitoring of ACC, not too threatening but also not an occasion to slack off.
 
You can disable the ACC under these conditions by holding down the distance control button for a few seconds.
 
I see the same, primarily on a stretch with scattered tree cover in medium angle sun where glare on the camera would come and go quickly. After a couple months driving the car I’m starting to recognize when it may struggle and it’s pretty consistent. It also doesn’t like rain if the wiper happens to skip at all in front of the camera.
 
I think the later cars (maybe post-2017?) have a slightly longer delay between the Bong and the car going into full regen. I've seen a few people describe it as "dangerous" but on my car the delay is long enough that it would only be a hazard to following cars if you were really not paying attention.

One further point - apparently the camera fogs up relatively easily (i.e. the small area in front of the camera can mist up even when the rest of the screen is clear) and you can counter this easily just by switching on the rear screen demist, which activates a heating element on the glass in front of the camera.
 
I have to wonder if blocking or shading the upper portion of the camera view could help. There is probably no easy way to do it, but experimenting with tape across the outside of the windshield could give us a clue if there is anything to be improved with that. I suspect it won't help much if at all though.
 
I suspect it would require more of a hooded overhang like an awning, but we would run into airflow / noise concerns not to mention interfering with the sweep of the wiper.
 
cpallenjr had the right answer above. When the sun gets in the eyes of the i3, you can turn off the adaptive part and change it into regular cruise control by holding down the distance button for a few seconds.

John Francis
Rolla, MO
 
You can disable the ACC under these conditions by holding down the distance control button for a few seconds.
Thank you, I realize it's probably in the manual, but I didn't catch that! This is very helpful for awkward sunlight or some rain conditions where it kicks off occasionally.
 
I suspect it would require more of a hooded overhang like an awning, but we would run into airflow / noise concerns not to mention interfering with the sweep of the wiper.
I wonder if it could be possible to just set the camera back more in a custom housing that does the same thing without exterior add-ons. (I have yet to take a close look at it though.) The crux of the problem may be in the windscreen glass itself though.
 
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