Possible Causes
WARNING: This page is about a different car, the 2004 Lexus ES 330. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic Trouble Code (DTC) 43/B1660 could be caused by an open, short, short to battery or short to ground in passenger-side air bag off indicator circuit or air bag sensor assembly malfunction.
NOTE:
During testing, if DTCs other than DTC 43/B1660 are retrieved, disregard them.