Here's the small gripe.

I have a 2011 is250. The problem is every now and then, the passenger chime alarm would go off with no one sitting in the seat. It also happens after someone gets out of the car and the passenger chime still goes off. The remedy that I've been doing is just buckling the passenger seatbelt to get it to stop. I know there's a way to turn off the annoying sound. I was thinking if the sensor in the seat is bad? or something electrical? What do you guys think?

 

I have this issue on my 07 is350. It doesn't go off randomly only when the passenger leaves the seat belt beeping still goes on for up to a minute after.

 

Have you brought it up to the lexus dealership?

 

Same here on my 09 350, it is annoying but I doubt they would do anything for it.

 

my 10 350 does it when the passenger gets out of the car but not randomly

 

I'm having this same issue on my 10 is350 currently. It's happening almost every single time I drive. I have to buckle the seat belt with nobody in the seat to stop it. Funny thing is, it still says passenger airbag OFF on the dash when the seatbelt is buckled. If someone is sitting in the seat, with seatbelt buckled, then it says airbag ON. Sorta confusing what's going on!