The generator provides DC voltage to operate the vehicle's electrical system and to charge the battery. A magnetic field is created when current flows through the rotor. The rotor is belt driven by the engine, creating an AC voltage as this field rotates within the stator windings. The AC voltage is converted to DC by the rectifier bridge and is then supplied to the electrical system at the generator battery terminal.
When the engine is running, the generator turn-on signal is sent to the generator from the PCM, turning on the regulator. The generator's voltage regulator controls current flow to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width modulated voltage 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 duty cycle of the regulator on the generator F terminal. The generator S terminal is connected to B+ voltage at the rear fuse block. The voltage is used by the regulator as a reference for system voltage control. The dash integration module (DIM) has a designated circuit for monitoring battery voltage connected to the S terminal circuit of the generator at the rear fuse block and to ground of the battery.
The PCM monitors F terminal and the L terminal, if a problem occurs the PCM will set DTC P0621 or DTC P0622 and sends a class 2 message to the instrument cluster requesting illumination of the battery charge indicator.
The dash integration module (DIM) monitors the battery voltage. The DIM sends system voltage status to the instrument cluster. If the instrument cluster detects a system voltage high or low condition, the instrument cluster illuminates the battery charge indicator and displays one of the following messages on the driver information center (DIC):
| • | With voltage less than 10.5 volts, the DIC displays BATTERY VOLTAGE LOW. |
| • | With voltage greater than 16.2 volts, the DIC displays BATTERY VOLTAGE HIGH |
If the instrument cluster detects a system voltage high or low condition and the engine speed is greater than 400 rpm, the instrument cluster will set the following DTCs:
| • | With voltage less than 10.5 volts, DTC B1513 will set. |
| • | With voltage greater than 16.2 volts, DTC B1514 will set. |
