PO674 Diagnostic Code on 2006 Ford F350 6.0L: Glow Plug Issue and GPCM Testing Guide

Model: 2006 Ford F350 6.0 L Fault Code: P0674 Posted: 2020-11-12 12:58

I've tested the resistance at the connectors leading to the GPCM and found it within specifications for all glow plugs. However, the PO674 diagnostic code returns immediately after being reset. This is causing me to suspect a faulty GPCM, though I'm unsure if there's a way to test the module before replacing it. It's also puzzling that only one glow plug appears affected—does this point to a specific component failure or a wiring issue? Any insights on diagnosing PO674 in 2006 Ford F35或 6.0L diesel trucks would be greatly appreciated.