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Home >> Ford >> 2003 >> Excursion 5.4 L, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 272 (MULTIFUNCTION Electronic Module System) >> Diagnosis And Testing >> Multifunction Electronic Module >> Principles of Operation
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Principles of Operation

WARNING: This page is about a different car, the 2003 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

The generic electronic module (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. Erratic or unexpected GEM function can often be traced to problems with these GEM inputs.

The GEM controls a variety of systems: