Lexus GS Alarm System Malfunction

I had something similar happen with my GS, though I can't remember the exact error code. The alarm would just randomly go off, or sometimes not arm at all. Have you noticed if your turn signals flash when you lock or unlock the car? Mine were doing that even when the alarm itself wasn't working properly. It's like the alarm control module is stuck thinking it needs to activate the optical locking confirmation.

Whoa, that's exactly what's happening! The indicators flash like crazy when I lock it, even though the alarm itself is dead. So, what did you do to fix it? Is it something I can tackle myself, or am I looking at a trip to the shop?

Yep, sounds like the same gremlin. Honestly, I wouldn't mess with it too much yourself unless you're really comfortable with car electronics. It could be a simple coding issue, but it could also be a deeper problem with the alarm control unit. I'd suggest taking it to a reputable shop that knows Lexus systems. They should be able to diagnose it properly and recode the alarm system if needed. Think of it like a computer needing a reboot, but for your car's security system.

Thanks a bunch for the insight! I took it to a workshop, and you nailed it – the alarm system was coded to activate the optical locking, causing the malfunction. They recoded it, and it's all sorted now. Cost me 45€, but totally worth it for the peace of mind.