Code 42 - Open Left Front Crash Sensor Circuit: Description
WARNING: This page is about a different car, the 1995 Mercury Mystique and 1995 Ford Contour. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic monitor supplies 10 volts to terminal 18 (Black/Green) of diagnostic monitor connector. Yellow/Red wire, from terminal 6, is connected to Black/Green wire inside left front crash sensor. If there is a voltage differential between terminals 6 and 18, Code 42 is recorded in diagnostic monitor.