Lexus LS Engine Wont Start

I also own an LS, and your problem sounds familiar. Have you checked the battery cable connections? I had similar symptoms – engine wouldn't start, complete silence. Turned out the cable connections to the battery were loose and corroded. I cleaned them up, tightened everything, and boom! Back to life! Were there any signs before this happened, like engine stalling or the check engine light coming on?

That's an interesting point! I admit I haven't specifically checked the battery cable connections. I assumed the battery was fine since the lights and radio work. But you're saying even if those work, bad connections could cause the engine not to start? Could you elaborate a little more on exactly what you did to fix it?

Yep, exactly! The lights and radio might draw enough power to function with poor connections, but the starter motor needs a HUGE surge of current. If those connections are bad, it won't get enough juice. I disconnected the cables completely (negative first!), cleaned the terminals and the cable ends with a wire brush (you can buy a special battery terminal cleaner too), and then reconnected everything TIGHTLY. If that doesn't do the trick, it could still be something more serious, and maybe it's worth visiting a trustworthy workshop.

You were spot on! I checked the battery cable connections, and they were indeed in terrible shape. Cleaned and tightened them as you suggested, and the car started right up! Took it to a shop to be extra safe and they confirmed that was the issue and charged me 155€ for cleaning the contact surfaces and re-tightening the screw connections. Thank you so much for your help.