Principles of Operation: Notes
WARNING: This page is about a different car, the 2005 Ford Pickup, 2004 Ford Pickup, and 2003 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.
The powertrain control module (PCM) controlled charging system determines the optimal voltage set point for the charging system and communicates this information to the voltage regulator. This system is unique in that it has 2 unidirectional communication lines between the PCM and the generator/regulator. Both of these communication lines are pulse-width modulated (PWM). The generator communication (GEN COM) line communicates the desired set point from the PCM to the voltage regulator. The generator monitor (GEN MON) line communicates the generator load and error conditions to the PCM. The third pin on the voltage regulator, the A circuit pin, is a dedicated battery voltage sense line.