Possible Causes
WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.
DTC 78/B1196 could be caused by an open in Yellow/Gray (circuit PLR+) or Yellow/Pink (circuit PLR-) wires in driver-side rear seat belt pretensioner squib circuit, driver-side rear seat belt pretensioner squib malfunction or air bag sensor assembly malfunction.
NOTE:
During testing, if DTCs other than DTC 78/B1196 are retrieved, disregard them.