Normal Operation

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

The PCM monitors the secondary generator output via the generator 2 monitor (GENMON) circuit. The PCM uses the generator 2 command (GENCOM) circuit to command the generator to either increase or decrease output. If the GENCOM circuit (generator control circuit) or the "A" sense circuit are open or shorted to ground, the PCM is unable to control the secondary generator output. When the engine speed is greater than approximately 2, 000 RPM, the generator defaults to a steady voltage output of approximately 13.5 volts and the PCM sends a message over the High Speed Controller Area Network (HS-CAN) to the Instrument Panel Cluster (IPC) through the Body Control Module (BCM) to illuminate the charging system warning indicator lamp.

DTC P163A (Generator Control Circuit) - The PCM sets this DTC if the GENCOM circuit or "A" sense circuit is open or shorted to voltage or ground.

This pinpoint test is intended to diagnose the following:

Fuse
Wiring, terminals or connectors
Secondary generator
PCM