Code 13 - Air Bag Circuit Shorted To Ground: Description
WARNING: This page is about a different car, the 1995 Ford Pickup, 1995 Ford F-Super Duty, 1995 Ford Cab & Chassis, and 1995 Ford Bronco. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic monitor measures voltage at terminals No. 11 and 12 of diagnostic monitor connector. Voltage at both terminals varies with charging system voltage. If diagnostic monitor measures a voltage of 2 volts or less at terminals No. 11 or 12, Code 13 will set. When Code 13 sets, diagnostic monitor blows its internal thermal fuse. This disables air bag deployment circuit. If short to ground is corrected, voltage at terminal No. 11 will return to normal, and Code 51 will set, indicating an open thermal fuse.