I have an '07 ES350 with the factory HID headlights. The driver side headlight will start to flicker a few minutes after being turned on and then eventually turn off. Turning the headlights switch off and then back on will turn this headlight back on but it will start to flicker again after a few minutes.

I had this problem last year with the same headlight and took it to the dealer who replaced the HID bulb but now it's back again. I've also noticed it seems to occur during the cold winter months and not so much during warmer weather.

The passenger side HID works fine with no problems. Any suggestions or trouble shooting tips would be appreciated. Perhaps it's a loose wiring connection but I'm not sure if this is something that can be checked without taking the entire HID assembly apart.

 

Since your driver's side bulb was replaced last year, there's a high chance that the bulb is good while the driver's side ballast is going.

Since you know for a fact that your passenger's side HID is good, the simple test is to swap the HID bulbs between driver and passenger side. Drive for a bit and monitor.

If the issue stays with the driver's side, then it's the driver's side ballast that is problematic would require replacement. Experts can chime in since I don't know, but I think the entire driver's light assembly needs to be replaced since the ballast should be an integral part.

If the issue migrated to the passenger side then it's the HID bulb at fault and you most likely got a dud from the dealership a year ago. And the fix is to get another HID bulb as replacement. There are plenty of option there from Sponsors on the forum or searching online. No need to get it from the dealership since this would be the most costly option.

 

after the dealer got 16k in work finished to my car after an accident in my 07 es350
there was no visible damage to the ballast or bulb but i was having a similar issue
i went in 3 times before it was resolved first time they just spent 3 hours turning them on and off waiting for it not to work properly
nothing happened they said come back if it happens again
so next time it happened i took a photo at night with the passenger headlamp turned off they decided they would replace the bulb a week latter to the exact day it didnt work again then a few more times over the week it stopped working properly then they decided they would replace the ballast with a used one they had sitting around a week latter it happend again so they told me to bring it in latter that day
they ordred a brand new ballast and bulb and headlamp assembly not sure why the entire assembly but the ballast the bulb and assembly they told me to come in they spent like 2 hours pulled the harnessing
replaced everything to do with the front lamp and it never happened again

 

Maybe they got tired of the shotgun approach and ran out of ideas of replacing each part (bulb or ballast) individually and replaced the entire assembly?

Also if your car has the Adaptive Frontlight System (AFS), then replacing the assembly ensures you have new motors and cogs to ensure that you won't have any headlight issues in the near future.