P0678 - Cylinder 8 Glow Plug Circuit

The ECM detected a fault in glow plug circuit for cylinder 8.

Code Overview

The ECM detected a fault in glow plug circuit for cylinder 8.

Common Causes

• Failed glow plug on cylinder 8
• Damaged wiring or connector at cylinder 8 glow plug
• Glow plug control module or power-supply issue

Diagnostic Steps

1. Inspect glow plug 8 wiring and connector condition
2. Check resistance and power feed to the glow plug circuit
3. Look for fuse, relay, or module faults before replacing parts

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

Browse the closest code-family pages when the same fault pattern often shows up nearby.

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.