DURAMAX-P0683 moderate Duramax ›

Glow Plug Control Module to PCM Communication Circuit

The DURAMAX-P0683 (Duramax) diesel fault code means: Glow Plug Control Module to PCM Communication Circuit. This is a moderate severity code.

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Keep driving?
Yes, with caution
DIY difficulty
intermediate
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What Are the Symptoms of DURAMAX-P0683?

  • Check Engine Light on
  • Hard starting when cold
  • Possible glow plug codes set alongside

What Causes DURAMAX-P0683? (Most Likely First)

  • Damaged wiring or a corroded connector between the two modules High
  • Glow plug control module fault Moderate
  • Poor power or ground to the glow plug control module Moderate
  • Engine computer fault Low

Can I Still Drive with DURAMAX-P0683?

Yes, with caution. DURAMAX-P0683 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.

Frequently Asked Questions

What does P0683 mean on a Duramax?

P0683 means Glow Plug Control Module to PCM Communication Circuit. The engine computer has detected a fault in the communication circuit between itself and the glow plug control module.

Is P0683 a Duramax-specific code?

No. P0683 is a generic OBD-II code defined by SAE J2012, so it means the same thing on any vehicle that sets it. The exact conditions GM uses to set it on its diesels are in GM service information.

Mechanics Guide Step-by-step diagnosis

How Do You Diagnose DURAMAX-P0683?

  1. Check power and ground at the glow plug control module.

  2. Inspect the communication wiring and connectors between the modules.

  3. Check whether the module responds before replacing it.

Sources 1

This page is built from documented references. Verify against your own service info before repair work.

  • SAE J2012Diagnostic Trouble Code Definitions (defines P0683 as a generic OBD-II code)

P0683 on Other Platforms

The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:

Gas / Automotive (OBD-II) Generic OBD-II definition for P0683

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More Duramax codes → Diesel home All diesel codes Heavy-duty Guides

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