Principles Of Operation
WARNING: This page is about a different car, the 2004 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
The GEM constantly monitors its subsystems for concerns. If a concern is found in one of the subsystems, the GEM will record the concern in the form of a diagnostic trouble code (DTC). The ignition switch position is very important to the GEM function. Often times, erratic or unexpected GEM function can be traced to concerns with ignition switch inputs.