F Terminal Circuit

Circuit Description
The F-terminal circuit from the generator is a pulse width modulation (PWM) signal to the PCM from the digital voltage regulator. The pulse width of the signal is proportional to generator output. The PCM monitors the PWM frequency to determine electrical load on the charging system.

Diagnostic Aids
A generator fault, such as a shorted output diode, malfunctioning regulator, an open or shorted rotor, or an open sense lead may cause a low battery charge. Refer to Charging System Check in Starting and Charging for further information and generator diagnosis.

F Terminal Circuit shorted to B+ causes GEN PWM to be fixed at approximately 70 %.