Hi I started to have a problem recently with my 09 LS460 AWD. When I start the car if I turn on my high beam the will turn on for a few seconds and then turn off and will never come back on. Even if I turn off my low beam to get the DRL on they will not light up. I have to turn off the car and restart it to be able to turn them on again for a few seconds before they shut off automatically. At first I thought that was the LED bulb that were dying (they worked perfectly fine before) so I changed them for brand new ones but the new ones are doing the same thing. I changed nothing on the car recently the battery is about a month and a half old. Could it be a relay or something like that?

Thank you for your help anything will help I know nothing about this car i bought it 2 months ago.

 

I encountered a similar issue with my 2008 Lexus LS 460, but it involved the low beams. In my case, the problem was a faulty Front Controller. The operation sequence for the headlamps in the 2008 LS 460 is as follows: The Headlamp output wire runs from the Windshield Wiper Switch directly to the Front Controller. From there, the front controller output is sent to the relay/fuse box, and finally from there it goes to the Low Beam Headlight Control ECU. The high beams, on the other hand, are connected directly to the high beam bulb from the fuse/relay box.

Based on my experience, I would recommend starting with the fuse box. It's a common culprit when it comes to electrical issues like this and can often be the source of the problem.

 

Thank you I will check this week end to see if this could be the problem

 

So today I checked the battery, starter and alternator with a tester and everything was fine. I connected a snap-on scanner to check the communication from the headlight ecu and the scanner could see that the ecu was receiving the command (high beam ON) so I'm pretty sure the headlight ECU is good but while the car was on but engine not started the voltage dropped from 13V to 6V in less than a minute witch is extremely quick I had to jump start the car. The battery is new (approximately 1-2 months old)

 

It sounds like there could be a significant parasitic drain or a faulty component that's drawing power too quickly, especially since your battery is relatively new. The sudden voltage drop from 13V to 6V in under a minute is unusual. There could be possibly be a issue in the electrical system. Even if headlight ECU is receiving commands, there could be an internal fault that causes it to draw too much current or cause a short when certain functions are engaged, such as the high beam.