Possible Causes
WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
DTC 88/B1166 could be caused by an open in Yellow/Violet (circuit ICL+) and Yellow/Orange (circuit ICL-) wires in left-side head impact air bag module squib circuit, left-side head impact air bag module squib malfunction or air bag sensor assembly malfunction.
NOTE:
During testing, if DTCs other than DTC 88/B1166 are displayed, disregard them.