Code 51 - Diagnostic Monitor Internal Thermal Fuse Open: Description

Diagnostic monitor measures voltages at diagnostic monitor terminals. When certain air bag deployment wires are shorted to ground, system may become susceptible to unwanted deployment of air bag. Diagnostic monitor senses a short to ground and helps prevent unwanted air bag deployment by blowing diagnostic monitor thermal fuse. Blowing this fuse removes all power (battery and back-up power) from air bag deployment circuits. If short to ground exists, diagnostic monitor will flash Code 13. If short to ground is intermittent and temporarily corrects itself, Code 51 will flash. If short to ground returns, Code 13 will flash instead of Code 51. If Code 51 is flashing and short to ground has not been repaired, an intermittent short to ground exists in air bag circuit. DO NOT replace diagnostic monitor unless short to ground has been located and repaired.