P0683 - Glow Plug Control Module (GPCM) To Powertrain Control Module (Pcm) Communication Circuit

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2007 Ford RV Cutaway, 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Econoline. However, it is still accessible from the selected car via links, so may be relevant.

P0683 - GLOW PLUG CONTROL MODULE (GPCM) TO POWERTRAIN CONTROL MODULE (PCM) COMMUNICATION CIRCUIT

Description:	The PCM carries out a functional key ON, engine running (KOER) self-test for the glow plug system. During that test the PCM enables the GPCM and monitors the GPCM/PCM communication circuit for concerns. When the PCM detects a concern with a GPCM/PCM communication circuit, the DTC is set.
Possible Causes:	GPCM/PCM communication circuit open in the harness GPCM/PCM communication circuit short to ground in the harness GPCM/PCM communication circuit short to voltage in the harness
Diagnostic Aids:	Diagnose DTC P0670 before diagnosing DTC P0683.
Application		Key On Engine Off	Key On Engine Running	Continuous Memory
All		refer to PINPOINT TEST AF .