Circuit/System Description
WARNING: This page is about a different car, the 2011 GMC Canyon and 2011 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.
The generator battery control module (GBCM) controls the generator through the turn on control circuit, or L-Terminal circuit. The control is a 5 V pulse width modulation (PWM) signal of 128 hz. Normal duty cycle when the engine is running is 5-100 percent.