I have a 15 RX with the HID headlights. I have only had it about 2 months now. I want to know if there is a way to have the headlight switch set to off and have the DRLs on. I know I can leave it in auto. My problem is that when it is in the garage the headlights turn on even during the day and that shortens the life of an HID dramatically. I have tried adjusting the sensitivity in the settings with no effect. This is my third Lexus with HID lamps. My first was a 2000 ES. When it was in the garage the headlights did not turn on even in auto. My mother has that car now and it still has the original lamps. (17 years, not bad) My second is a 2006 SC430 that I still own. I left that on auto and the headlights came on every time I started the car in the garage and the HID lamps burned out in about 6 years. Changing them on an SC is extremely difficult so I decided to turn the headlights on manually. When you turn that system to off the DRLs stay on. With the current RX when the system is in the off position the DRLs are turned off also. In my opinion, very stupid. I have Techstream and can access the on board computer.

Am I missing something?

 

You seem to have the correct understanding of the USA system (Canadian cars can not defeat the mandated DRL's)

 

Gosh, I'd just leave the switch in Auto and enjoy the way it works. I think your SC was an exception. The HID bulbs and even the halogen high beam bulbs in my last LS were still the original ones when I sold the car at 13 1/2 years / 180,000 miles. Having the low beams come on for a few seconds in the garage during daylight hours many thousands of times didn't shorten the bulbs lives.

I particularly value how the headlight AUTO setting causes the headlights to switch on/off when entering and exiting tunnels and parking garages.

If you are that obsessive, I suppose you could flick your headlight switch to OFF before starting your engine in the garage and then flick it back to AUTO after you exit the garage.