Theory Of Operation
WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
There are two communication lines between the Powertrain Control Module (PCM) and the Generators. Based on sensed Battery voltage, the PCM commands Generator 1 and Generator 2 to charge both Batteries to a desired voltage. The maximum voltage the PCM will command the Generators to charge is 14.75-Volts. The PCM then receives feedback from both Generators reporting the voltage level it is charging the Batteries. The PCM will not light a MIL lamp for this fault, but the ETC lamp will be on solid.