High beam not working on auto

[westo3]

Was driving the other night when I noticed that the lights never went onto full beam. They dipped with on coming traffic but never went all the way up when the road was clear. When I switched to manual full beam they lit up for more road than when on auto. Has anybody experienced this?

[NemesisUK]

Do you have adaptive headlights, not simple auto lights? If so the adaptive high beam will change the range dependent on speed. I notice on my RX the high beam range extends significantly at speeds above 60mph but the beam pattern is much broader at lower speeds.

[westo3]

Thanks Peter, yes I do have adaptive auto lights and that could be the reason, will check it out next time

[NemesisUK]

2 hours ago, westo3 said:

Thanks Peter, yes I do have adaptive auto lights and that could be the reason, will check it out next time

You may find this Lexus EU tech doc interesting but keep in mind it's for the 2020 RX, there may be differences in how  your 2017 GS operates.

 

LIGHTING SYSTEM CONTROL ADAPTIVE HIGH-BEAM SYSTEM (AHS).pdf

[westo3]

Thanks Peter. Very useful,  I did not realise it was related to speed to such an extent. At the time in question I was going fairly slow hence the lower beam. Thanks again.

[Smiggy2]

That is great, thanks!  But why /what does it mean  "the dimmer switch is set to LO" does that mean low beam or something else? But then it would never go to high beam?

 

FUNCTION a. The adaptive high beam system operates when the adaptive high beam system switch is on, the light control switch is in the HEAD or AUTO position and the dimmer switch is set to LO. The adaptive high beam system uses the forward recognition camera to detect the headlights of oncoming vehicles and the taillights of preceding vehicles and to determine the brightness of the surrounding area in order to automatically adjust the light distribution from the headlights.

[westo3]

The light stalk should be set to high beam