You have to be going at least 30MPH; at least that's how they work in my 2015 Ultimate
Actually 22 mph. I found this in the manual.
When the Smart High Beam is operating,
the high beam switches to low
beam in the below conditions.
- When the headlamp is detected
from the on-coming vehicle.
- When the tail lamp is detected
from the front vehicle.
- When headlamp/tail lamp of bicycle/
motorcycle is detected.
- When the surrounding is so bright
that high beams are not needed.
- When streetlights or other lights
are detected.
- When the light switch is not in the
AUTO position.
- When the Smart High Beam is off.
- When vehicle speed is below 22
mph (35 km/h).
So, based on the above, if I slow down to 20 mph approaching a dark turn and now can't see I should speed up to get the lights back on. I've been in a couple of situations where I was using the auto high beam and made a turn into a dark road and the lights did not go back on, probably due to lower speed. That seems insane to me. They work great for miles, then when you turn to a road where the high beam is a necessity, they may not come on.