Circuit/System Description

The generator battery control module (GBCM) controls the generator through the generator turn on signal circuit, or L-Terminal circuit. The signal is a 5 volt pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is 0% when the engine is off. If the generator turn on signal circuit is 65 percent or greater duty cycle, or pulled high to positive voltage, when the GEN L-Terminal Signal Command is 0%, then DTC B1488 will set.