The generator provides the voltage that operates the electrical system and charges the battery. A magnetic field is created when current flows through the rotor windings. This field rotates as the engine rotates the rotor, creating an AC voltage in the stator windings. A rectifier bridge converts the AC voltage to a DC voltage. This DC voltage is then supplied to the electrical system at the battery terminal.

The current supplied to the rotor controls the amount of output voltage. The regulator in the generator uses digital techniques in order to control the current supplied to the rotor. The rotor current is a regulator-supplied series of electrical pulses. When the ignition switch is first placed in the RUN position, the pulse width is very narrow. This causes the rotor to produce a weak magnetic field. This produces a lower output voltage to the electrical system. Once the engine is running, the regulator monitors the output voltage through an internal wire and changes the pulse width accordingly.

The powertrain control module (PCM) or vehicle control module (VCM) turns the generator ON or OFF, by applying voltage to the generator control/monitoring circuit 225 (RED). The regulator in the generator also requests the charge indicator located in the instrument panel cluster (IPC), using the same circuit. When the regulator monitors that either a voltage high or voltage low condition exists with the engine running, a ground path to the PCM/VCM will be provided through the generator control/monitoring circuit 225. The PCM/VCM then sends a serial data message to the IPC requesting the charge indicator to be turned ON. The IPC monitors serial data messages from the PCM/VCM, and turns the charge indicator ON when requested.