Possible Causes
WARNING: This page is about a different car, the 2002 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.
DTC 53/B0105 could be caused by a short between P+ (Yellow/Red wire) and P- (Yellow/Green wire) in squib circuit, squib malfunction or air bag sensor assembly malfunction.
NOTE:
During testing, if DTCs other than DTC 53/B0105 are displayed, disregard them.