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Home >> Hummer >> 2010 >> H3T Base, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 23 (Battery, Charging System And Starting System) >> Diagnostic Information and Procedures >> DTC P0621 >> Circuit/System Description

Circuit/System Description

WARNING: This page is about a different car, the 2010 GMC Canyon and 2010 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.