I used to think when I flash it'll turn on the high beam only but that's wrong. Today I changed the high bulbs 9005 to a brighter pair trying to get a better DRLs, but when I tested the high beam by flashing I realized it turns both low & high beams on at the same time. I have HID for low beam so that's not a good thing for me to flash. And I think I did it only one time in the past but now I won't do it again. Is your car doing the same when flashing?
Yes, they both turn on when pulling back on the light stalk (flashing). Also note that the DRL (daytime running light) position turns on just the high beams, albeit at a lower voltage. Prior to putting in replacement 2005 bulbs (Sylnania Ultras), I called them up to see if running them at a lower voltage as running lights would have an effect on the already short life span of these bulbs. They said that it should be ok, but that they hadn't heard of DRL's that did this.