Cylinder 6 Glow Plug Circuit
The DURAMAX-P0676 (Duramax) diesel fault code means: Cylinder 6 Glow Plug Circuit. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $30-$80 per glow plug + labor; full set $250-$600
Down with a Duramax fault on the road?
We are building a network of verified mobile diesel and reefer technicians along the freight corridor. It is not live yet — no one can be dispatched to you today. You can see where the pilot is launching and register interest.
View pilot availability →What Are the Symptoms of DURAMAX-P0676?
- Hard start in cold weather
- White smoke at start-up
- Rough idle until warm
- Check Engine Light (may take one cold start to set)
What Causes DURAMAX-P0676? (Most Likely First)
- Failed glow plug on cylinder 6 Very Likely
- Glow plug controller / relay fault Likely
- Broken glow plug tip — requires head removal (LLY/LBZ had 'swelled' glow plug failures) Possible
- Open or damaged glow plug wire Possible
Can I Still Drive with DURAMAX-P0676?
Yes, but fix soon. DURAMAX-P0676 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What is P0676 on a Duramax?
Duramax code P0676 (Cylinder 6 Glow Plug Circuit) is a moderate-severity diagnostic trouble code triggered by the engine control module when it detects a problem in the associated system. On LLY/LBZ engines, glow plugs can swell and break inside the head — always unscrew them slowly while monitoring torque.
Is a Duramax P0676 safe to drive?
Yes in warm weather. In cold weather, a failed glow plug makes cold starts difficult and increases engine wear.
How much does it cost to fix P0676 on a Duramax?
Individual glow plug replacement is $30-$80 parts, 1-2 hours labor. Many owners replace all 8 if multiple are failing.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DURAMAX-P0676?
Measure resistance across each glow plug — should be ~0.5-2 ohms, open = failed
Command glow plug 'on' with scan tool and verify battery voltage at the plug tip
Pull failed glow plug slowly — if it's swelled / broken, professional extraction may be required
Replace glow plug with OEM or Motorcraft-equivalent; torque to 18 ft-lb
Monitor for return after one or two cold starts to confirm repair
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines P0676 as a generic OBD-II code)
P0676 on Other Platforms
The same code ID appears across other engines, vehicles, and equipment. Diagnostic flow varies by platform — see the matching breakdown:
Which Vehicles Commonly Get DURAMAX-P0676?
- 2001-2004 Chevy Silverado 2500/3500 HD 6.6L Duramax LB7
- 2001-2004 GMC Sierra 2500/3500 HD 6.6L Duramax LB7
- 2004.5-2005 Chevy Silverado 2500/3500 HD 6.6L Duramax LLY
- 2004.5-2005 GMC Sierra 2500/3500 HD 6.6L Duramax LLY
- 2006-2007 Chevy Silverado 2500/3500 HD 6.6L Duramax LBZ
- 2006-2007 GMC Sierra 2500/3500 HD 6.6L Duramax LBZ
- 2007.5-2010 Chevy Silverado 2500/3500 HD 6.6L Duramax LMM
- 2007.5-2010 GMC Sierra 2500/3500 HD 6.6L Duramax LMM
- 2011-2016 Chevy Silverado 2500/3500 HD 6.6L Duramax LML
- 2011-2016 GMC Sierra 2500/3500 HD 6.6L Duramax LML
- 2017+ Chevy Silverado 2500/3500 HD 6.6L Duramax L5P
- 2017+ GMC Sierra 2500/3500 HD 6.6L Duramax L5P
Explore More
Was this helpful?
Send this to whoever is fixing the truck — your tech, or the person asking what the fault means.