2000 Ls400 Automatic Light Sensor Problem

[KJK]

Hey Guys,

I'm a proud new owner of 2000 LS400 Platinum edition. She's got 150K miles but still drives beautifully. The only electronic glitch I have is that the automatic light sensor doesn't seem to work. When I put my headlight to Auto Position, it failes to turn on as it gets dark outside. GPS screen doesn't turn to night mode either for the same reason. Any suggestions as to where I should start? Thanks in advance.

[1990LS400]

The repair manuals for my 2000 LS400 say to check the following when the "Automatic light control system does not operate":

1) ECU-1G Fuse (Instrument Panel J/B)

2) Dome Fuse (Engine Room J/B)

3) Automatic Light Control Sensor

4) Light Control Switch

5) Door Courtesy Switch

6) Body ECU

7) Driver Door ECU

8) Wire Harness

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I assume that the fuse mentioned in #1 is in the underdash fuse box and that the dome fuse is in the engine compartment fuse box.

The light control sensor mentioned in #3 is on the dash on the driver's side. When it's working, laying something on top of it can cause the low beam headlights and tail lights to be on during the day.

There are lots of pages on diagnosing this problem -- way too many to scan and post here. If you would rather not purchase a manual, you can view diagnostic information for a fee at https://techinfo.toyota.com

Also, the sensitivity of the automatic light control system can be adjusted -- I posted information about that in this thread: http://us.lexusownersclub.com/forums/index...299&hl=CBES

Post photos of your car when you can -- it's always fun to see another Platinum LS400.

[Daddy4302]

     I have a 05 LS430 my auto lights will not turn off after the head light bulbs were changed. Any remedies? Help Appreciated!

[vissine]

The light sensor is on the dashboard. On my car, it is located next to the VIN. I would start from there. See if it is cracked or not.