Hi everyone. I just bought a 23 is350. It is my first time owning a Lexus. Comparing to my previous cars, its headlight response time is way slower. If I block the sensor with my hand, the brightness of screen drops instantly but the it takes about 10 seconds for the headlight and indoor ambient light to turn on. Everytime I drive into a covered parking lot or tunnel I have to turn light on manually myself.
I am wondering is there a way to adjust its response time ? I am sure this is not a sensitive issue. Is this normal for Lexus?

 

There is an auto headlight on-off sensitivity setting in the infotainment. Have you tried adjusting that up or down?

 

I love this forum, learn something new everyday about the car I have owned for 2 years!

I just also learned about the setting to stop the "Eco" light from showing up on the gauge cluster.

 

That does not help in this case since it only change the threshold of light to trigger the headlight. I am thinking there is a delay setting somewhere. Because I can tell the sensor woks as after I block the sensor it lower the brightness of the screen quickly.

 

I would say that my car takes around 5 seconds to turn on the headlights when I go into a tunnel or dark overpass or something like that - perhaps a bit less if it's a particularly shady parking garage. Either way, 3-5 seconds. Is that about right for you as well? I've owned 3 ISes, and all have been the same in this regard.

 

I have the same annoyance, OP. The headlight sensitivity setting has no effect on how long it actually takes for the headlights to come on. There's a fixed timer that is independent of the light sensitivity.

Even worse, the headlights do not come on automatically when its raining and the windshield wipers are on. This weekend, I had to turn on the headlights manually because rain caused some very low visibility on the highway, and the ambient light during the daytime was preventing the headlights from coming on.