Conditions for Setting the DTC
WARNING: This page is about a different car, the 2003 Buick Regal, 2003 Buick Century, 2002 Buick Regal, and 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
The generator turn on signal circuit voltage is low while the PCM is commanding the generator on and the condition is present for more than 30 seconds. Or the generator field duty cycle signal PWM is less than 5 percent and the engine RPM is less than 2,500. If the conditions are present for more than 30 seconds the DTC will set.