Cylinder 8 Glow Plug Circuit
Can I Drive?
Yes, But Fix Soon
DIY Difficulty
beginner
Estimated Cost
$50-$300
What does POWERSTROKE-P0678-67 mean?
The POWERSTROKE-P0678-67 (Power Stroke) diesel fault code means: Cylinder 8 Glow Plug Circuit. This is a moderate severity code.
Common Symptoms
- Hard cold start
- White smoke
- CEL
Probable Causes (Ranked by Likelihood)
- Failed cylinder 8 glow plug Very Likely
- Harness damage Likely
- GPCM fault Possible
Step-by-Step Diagnostic Procedure
Measure GP resistance (0.5-2 ohms).
Inspect harness and GPCM.
Frequently Asked Questions
What is P0678 on a 6.7L Power Stroke (Scorpion)?
P0678 on a 6.7L Power Stroke (Scorpion) (2011-present) indicates: Cylinder 8 Glow Plug Circuit. This is a known diagnostic trouble code on this engine family and typically points to the causes listed above.
Can I drive with P0678 on my Power Stroke?
Yes, you can generally drive with this code, but diagnose it soon to prevent further damage.
How much does it cost to fix P0678?
Repair cost is typically $50-$300 depending on the underlying cause and whether you DIY or use a shop. Diagnostic time alone runs $100-$180 at most independent diesel shops.