Tail lights come on after vehicle is shut off

[bendutton17]

So I just bought myself a 2005 LS430 after a few years of searching. I've had it a little over a month and I absolutely love it. However, over the last couple days, I've noticed my tail lights coming on for seemingly no reason. First time I noticed, I thought it was just a trick of the light, as the sun was getting low and figured it was just the sun hitting my lights just right to give the illusion of them being on. Fast forward to this morning; I had to leave earlier than usual for work, so around 4:45am, came out my front door, and low and behold, clear as day, my tail lights are on (not brake lights, just tail lights, and literally nothing else). My first thought was "uh oh, did I leave my lights on all night?" Which I was all but certain I hadn't. After confirming they were in fact off, next thing I checked was my brake pedal. Didn't seem anything out of the ordinary, but just to see, I tried gently lifting it off it's rest point, to no result. Kicker was that, unbeknownst to me at that moment, as soon as I hit my keyless entry, lights immediately went off. Upon discovering the lights were off, I went to work like normal. Fast forward another hour or so, I get a message from a co-worker saying my tail lights are on. So now I know there's clearly an issue. After a quick search online, I couldn't find much, but I did find something about a possible ECU in the trunk, or 'luggage room' as was described on the website. When I returned to my car after my delivery, the tail lights were on again. So I decided to test something; I hit the unlock on my keyless entry, and then waited. As soon as I hit the button, lights went off. Then, after around 30 seconds, they came back on. Then tried the lock button, same result. So fast forward again to the end of my work day: I go run some errands real quick and head home. When I got home, my first instinct was to pop the truck to make sure no water was getting into places it shouldn't, and thankfully found no evidence of that. But the lights would still come on after about 30 seconds of hitting a button on my keyless entry. Now for the real interesting part: after feeling stumped, I popped the hood, as I was going to disconnect the battery to make sure it wouldn't drain, I had to run inside to grab my tools, so I closed the hood, ran in, and when I got back, the lights were off, and staying off. I've been home for about 45 minutes now, and keep checking regularly, and they haven't come back on yet (knock on wood). Any ideas as to what the issue could be? I've seen potential for it to be something as minor as a fuse to as major as a wiring harness. Any suggestions or ideas would be a hug help, thanks!

[RX400h]

Quote

It seems like you’re experiencing an issue with the tail lights on your 2005 LS430. This could be due to a variety of reasons. Here are a few possibilities based on similar issues reported by other Lexus LS430 owners:

1. Faulty Sensor: The tail light sensor might be malfunctioning. Even though the lights illuminate, the sensor checks wattage draw. If the left side is drawing 20 watts, and the right side is drawing only 10 watts, and the circuit is looking for a 40 watt draw, the warning light will come on.

2. Electrical Issue: There could be a loose, frayed, or damaged wire causing the tail lights to come on. It’s suggested to remove the trim in the trunk and look for any such issues.

3. Keyless Entry System: The issue might be related to the keyless entry system, as you’ve noticed the lights go off when you hit a button on your keyless entry, and then come back on after around 30 seconds.

4. Bulb Issue: There could be an issue with the tail light bulbs themselves. If your turn signal doesn’t blink, or blinks rapidly, you likely have a burnt out bulb.