Normal Operation: Notes

The PCM monitors the generator output via the generator monitor (GENMON) circuit. The PCM uses the generator 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 will not be able to control the 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 request to the Instrument Panel Cluster (IPC) to illuminate the charging system warning indicator. A GENCOM circuit fault can be confirmed by viewing the PCM PID generator command line fault (GENCMD_LF) (YES status indicator fault).

• DTC P0620 (Generator Control Circuit) - The PCM sets this DTC if the GENCOM circuit or "A" sense circuit are open or shorted to ground.

This pinpoint test is intended to diagnose the following: 

• Fuse
• Wiring, terminals or connectors
• Radial arm adapter
• Generator
• PCM