Pinpoint Test C : DTC P0620: Notes

WARNING: This page is about a different car, the 2015 Lincoln MKS. However, it is still accessible from the selected car via links, so may be relevant.

Diagnostic Overview

Diagnostics in this article assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Service Information for more information.

Refer to Charging System , for schematic and connector information.

Normal Operation and Fault Conditions

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 and the generator defaults to a steady voltage output of 13.5 volts and the PCM sends a request to the IPC to illuminate the charging system warning indicator. A GENCOM circuit fault can be confirmed by viewing the PID generator command line fault (GENCMD_LF) (YES status indicator fault).

Visual Inspection and Diagnostic Pre-checks

Before diagnosing or repairing the charging system inspect the following items:

Fuses and fusible links
High current BJB for loose or corroded connections
Radial arm adapter
Wiring, terminals or connectors

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Conditions
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
Generator
PCM
Radial arm adapter