Since having the car, about 7 months agol haven't done much driving in the dark. Had figured the way the auto dip works some time ago. Travelling  the last two mornings there was  dense fog in patches. It totally screwed up the sensing, switching between high and low beam very erratically. Then even when it cleared for longer periods l had to dip manually sometimes for approaching vehicles. In the end my driving was so distracted by was it going to dip before I blinded traffic coming the other way I switched to manual control. System bit hit and miss to me.

I’d imagine the light reflecting off the fog was fooling the system into thinking there was another vehicle coming towards you. 
 

These systems are all there to assist, not take over completely. Sometimes, manual control is required. 

It works using a camera, I'm not surprised fog confuses the hell out of it 

I tried the HBA system a couple of times during our 3 years, but found it totally unacceptable no matter the weather.

 

Now it’s winter time the lamp switch just lives in the ON position.  Full manual control. Love it.

2 hours ago, benterrier said:

System bit hit and miss to me.

 

Fog is just water so the camera lens is buggered.

 

Your distance cruise control, lane keeping assist and front assist also have trouble working when water's introduced in to the equation. All this talk of fully autonomous vehicles...  technology that works is a very long way off.

 

I have auto high beam lights - they work perfectly when the weather is OK.

Edited 25 October, 20196 yr by Guest

Could it be the sensor being tricked by the fog particles reflecting back. If it persists I'll get it booked in

Yes guys, manual controls, we've been using them along time.

16 minutes ago, benterrier said:

Could it be the sensor being tricked by the fog particles reflecting back. If it persists I'll get it booked in

 

Could be. If the fault persists when the weather is fine then book it in, but not because they don't work in poor weather

 

One sensor that does work in rain is the auto-wiper, but then even during a drought, the wipers will on occasion swipe on the auto setting because things like flies hit the sensor and the car's fooled in to thinking it's raining.

 

Aircraft systems rely on data picked up by pressure sensors. On occasion those sensors become blocked by ice or even tiny animals building their nests and next thing you know the aircraft looses control and crashes. A perfectly good working sensor is only as good as the info it's fed. 

Edited 25 October, 20196 yr by Guest

5 minutes ago, Scot5 said:

Could be. If the fault persists when the weather is fine then book it in, but not because they don't work in poor weather

Yes thanks Scot5 I'll take your advice.

Doesn't the car know to adjust the headlights when you turn the fog lights on. In the same way it knows to adjust the beam dependant on your speed.

That's why its called a driver assist system and not automation. Its only there to assist. 

For full automation you have to engineer the system to a whole new level of fault-tolerance, that may be essential in commercial aircraft but its a long way away from being essential or economic in consumer automobiles. 

9 hours ago, tunedude said:

Doesn't the car know to adjust the headlights when you turn the fog lights on. In the same way it knows to adjust the beam dependant on your speed.

 

Something to try, does turning on either the front or rear foglights disable the High Beam Assist feature.

 

I guess the fog isn't necessarily dense enough to justify the use of the fog lights.