The generator provides voltage in order to operate the vehicle's electrical system and in order to charge the battery. A magnetic field is created when current flows through the rotor. This field rotates as the rotor is driven by the engine, creating an AC voltage in the stator windings. The AC voltage is converted to DC by the rectifier bridge and the voltage is supplied to the electrical system at the battery terminal.

With the ignition ON, the volt/charge indicator illuminates during the bulb check. When the PCM identifies a condition in the charging system, the PCM sends a command for the indicator to the IPC through the Class 2 data stream.

When the ignition switch is placed in the RUN position, voltage is supplied to generator terminal L by the powertrain control module (PCM). This turns on the regulator. The generator's voltage regulator controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator F terminal is connected internally to the voltage regulator and externally to the PCM. The PCM monitors the field voltage on the generator F terminal.

When the ignition switch is turned to RUN, the charge indicator turns on for a few seconds (bulb check), then turns off. The PCM commands the charge indicator bulb to turn on by sending a Class 2 serial data line message to the instrument cluster when the PCM detects a charging system problem.