The generator provides voltage to operate the vehicle's electrical system and to charge its 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 voltage by the rectifier bridge and is supplied to the electrical system at the battery terminal.

The generator's digital regulator uses digital techniques to supply the rotor current and thereby control the output voltage. The rotor current is proportional to the width of the electrical pulses supplied by the digital regulator. When the ignition switch is on, voltage is supplied to terminal L from the powertrain control module (PCM), turning on the digital regulator. Narrow width pulses are supplied to the digital rotor, creating a weak magnetic field. When the engine is started, the digital regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the digital regulator varies the field current by controlling the pulse width. This regulates the generator output DC voltage for proper battery charging and electrical system operation. Voltage is supplied at all times from the GEN fuse in the underhood accessory wiring junction block through circuit 2740 to terminal S of the generator. This is used to provide a better battery voltage measurement. The powertrain control module also monitors the generator using terminal F through circuit 23.

The powertrain control module (PCM) controls the charge indicator lamp in the instrument cluster. The PCM sends a message to the instrument cluster through the Class II serial data link to turn on the charge indicator lamp when detecting one of these conditions:

For more information regarding the operation of the instrument cluster, refer to Instrument Cluster Circuit Description Instrument Panel, Gauges and Console.