CJITTY

Hey Everyone,

Did a search and can't find a similar story. I was sitting here in the house. Car is parked right outside in driveway for about an hour after a quick drive up the road. It's about 70 degrees and sunny out.. no wind, no kids around nothing. Windows and sunroof closed. Alarm just starts going off?? I go out and there is nothing wrong with the car. Starts up just fine, etc.

Has this happened to anyone and why would it do that?

I got 1000K left on the factory warranty, probably have them look into it when I take it in for next oil change.

Thanks in advance

JFNash

Key reprogramming, maybe?

CJITTY

hmm, thought about that as well. I see from some google searching I have been doing that random false alarms is somewhat an issue on various Lexus models. One guy stated on edmunds town hall site that he came out and his windows and sunroof were open one morning on his 08 LS!?!?! So that would lead me to believe a key reprogramming may be in order as well based on that, but that doesn't explain what triggers it...I'll let the dealer "deal" with it

JSTALEX

Hope your not sitting on your Key Fob!

CJITTY

LOL, keys were on counter

JSTALEX

Just had to ask!

jmcraney

Was your alarm system "armed" when this event occurred?

CJITTY

Yes Sir..i'm in the habit of double clicking lock on the key fob, so I am pretty sure it was armed. Would the system yell at me if I didn't have it armed? I would assume it would just lock and perhaps arm itself after so much time passed? I dunno

jmcraney

If your system was armed when this occurred you have two things to consider.

One is that one of the sensors on your car is defective such that your car thought a door had been opened or something like that.

The other thing that you need to think about is that your car received a spontaneous "panic alarm" transmission from one of your remote keys. The panic alarm will work regardless of the armed state of alarm system.

I have tried to explain about spontaneous transmissions from the remote keys here: https://www.clublexus.com/forums/5811770-post35.html

A "panic alarm" transmission, whether spontaneous or actuated, would be much like a "major ventilation" (my term for lowering the windows and opening the sun roof) transmission, both requiring holding the remote key button depressed for several seconds. That several seconds of operation can be emulated by crystal growth in the remote key.

Your system will not notify you audibly if it is not armed and it will not auto-arm.

CJITTY

that is some great info! I appreciate it! Looking forward to doing your wind noise fix, great write up

RGSW

I had the trunk open twice in my garage without my command on my 2008 LS460. I also had the windows and sunroof open in the garage without my command. Several months ago, I made a hard leather pouch for the Key Fob and neither has reoccurred yet. I wrote it off to pressing the key fob in my pocket?

JFNash

I wouldn't be surprised to hear all kinds of stories about Lexus remote key system going crazy.

One time I was parking my 460 in a parking lot where there was another 460 (07-08) parking right behind me. I got off the car, shut the door and locked the doors using the button on the door handle. When I pressed the button, the other LS460's lights flashed twice (as if someone pressed the lock key on its key fob)!!

I tried to replicate what happened many times, but it didn't occur again.

My car will also act up from time to time. I lock the doors, walk away then I'll see/hear the doors unlocking again. After 30 seconds the car will lock itself (as I configured it to lock after 30 seconds if the door isn't opened).

Weird.

CJITTY

Hmm, weird stuff. Mine hasn't done that since, but my key fob was sitting on the kitchen counter when this happened. In fact, I was runnin around for second trying to locate it to shut it off, so I know it wasn't from an accidental pocket push. I'll keep an eye on it. With all the frequencies in the air, bluetooth, military bases and whatever else, I guess this kind of random stuff can happen. The bad door, hood, trunk sensor may be the most likely cause. I'll tell Lexus when I am in for my next oil change in a week or so

Brainez

I know this post is old but I bought my 08 ls460 2 months ago and it has been parked in my garage for a couple weeks waiting for parts I have had the alarm go off 9 tims for no reason at all even unplugged the horns. Then today a weird second alarm noise went off at 2 in the morning. No matter if the car is locked or even unlocked it would set the alarm off even left my fob in it unlocked and the alarm went off I'm loosing my mind over this any help would be great

KYLS

I'd suspect one of the key FOBs and try removing the batteries from all to see if that resolves it. Good luck.