GM Service Manual Online
For 1990-2009 cars only

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 by the rectifier bridge and is supplied to the electrical system at the battery terminal.

When the ignition switch is on, voltage is supplied to terminal L by the Powertrain Control Module (PCM), turning 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.

The PCM commands the charge indicator on by ground the charge indicator control circuit when the PCM detects a charging system problem.

The generator features permanently lubricated bearings. The generator is replaced as a complete unit, service should only include the tightening of mounting components.

Application

Specification

3.4L LA1

Model

  1. Bosch KCB2
  2. Bosch NCB1

RPO Code

  1. K68
  2. KG9

Rated Output

  1. 105A
  2. 140A

For more information regarding the Charging System, refer to Charging System Description , and Charging System Circuit Description in Engine Electrical.