DTC 31/B1100: Air Bag Sensor Assembly Malfunction: Description
WARNING: This page is about a different car, the 2004 Toyota Matrix and 2004 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
The air bag sensor assembly consists of an air bag sensor, safing sensor, drive circuit, diagnosis circuit and ignition control circuit. The air bag sensor assembly receives signals from air bag sensor, judges whether or not the air bag must be deployed and diagnosis system malfunction.