DTC 72/B0138: Short To Battery In Driver-Side Seat Belt PRETENSIONER Squib Circuit: Description
WARNING: This page is about a different car, the 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
The seat belt pretensioner squib circuit consists of the air bag sensor assembly and driver-side seat belt pretensioner. The squib circuit causes the seat belt pretensioner to deploy when deployment conditions are satisfied.