One problem related to air bag light on has been reported for the 2011 Lexus LX570. The most recently reported issues are listed below.
The airbag light comes on in the dash indicating a problem with the system. The passenger airbag light also indicates the passenger airbag is off. The light was coming on intermittently, but now it comes on 90% of the time as soon as I start my vehicle. I took it to the dealer today and it cost me $100 just for them to look at it. The dealer states it could need a new seat belt tension sensor power source which is $650. They are not sure if it will correct the problem or require additional parts. I did a search on the internet and the issues is documented on many forums. I believe the car manufacturer should cover the issue since they are aware of the problem.