LEMON Manuals: Even more car manuals for everyone
Home >> Mercury >> 2008 >> Milan Base, 2.3 Z, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 1408 (Interior Lighting System) >> Diagnostic Tests >> Interior Lighting >> Principles of Operation >> Field-Effect Transistor (FET) Protection (MKZ Only)

Field-Effect Transistor (FET) Protection (MKZ Only)

WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

The SJB utilizes a protective circuit strategy for many of its outputs (for example, the headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault is detected. The circuit then resets after an ignition cycle or customer demand of the function (switching the component on, battery saver being energized). When an excessive circuit load occurs several times, a continuous DTC is stored and the module shuts down the output until a repair procedure is carried out. At the same time, the continuous DTC that was stored on the first failure cannot be cleared by a command to clear the continuous DTCs. The module does not allow this code to be cleared or the circuit restored to normal until a successful on-demand self-test proves that the fault has been repaired. After the on-demand self-test has successfully completed (no on-demand DTCs present), the continuous DTC clears and the circuit function returns.