Code 15
WARNING: This page is about a different car, the 1995 Toyota Paseo. However, it is still accessible from the selected car via links, so may be relevant.
Indicates open +S or -S circuit between front air bag sensor and center air bag sensor; short to battery voltage in +S circuit between front air bag sensor and center air bag sensor; faulty front air bag sensor; faulty electrical connection check mechanism in front air bag sensor connector; or faulty center air bag sensor.