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DTC code page

P0676: Cylinder 6 Glow Plug Circuit/Open

Quick answer: The ECU detected an open or fault in the cylinder 6 glow plug circuit.

Drivers also search this fault as cylinder 6 glow plug circuit, glow plug 6 open, cylinder 6 preheat fault.

Severity: medium Family: powertrain Related paths: 10
Meaning

What P0676 usually means

P0676 marks cylinder 6 as the weak link in the preheat system. On a diesel that spends nights outdoors or operates in colder seasons, one non-functioning plug can noticeably stretch crank time and create a short-lived rough idle after the engine starts. The code should be read as a targeted starting clue, but not an excuse to ignore shared controller, feed, or harness conditions that may be aging at the same time.

Fast triage

Start here before chasing parts

  • Scan first: save freeze-frame and pending codes before clearing anything.
  • Confirm the complaint: compare the stored code with current drivability symptoms.
  • Use context: trims, live data, and related codes usually narrow the fault faster than guesswork.
  • Work simplest to hardest: leaks, connectors, maintenance items, and known patterns before expensive components.
Initial checks

What to check first

  • Verify cylinder numbering so you test the correct plug on the first pass.
  • Compare resistance and connector condition with the other cylinders for context.
  • Check whether the complaint aligns with cold starts rather than warm restarts.
Driving risk

Can you keep driving?

P0676 usually affects cold starts more than warm operation, but repeated delay makes the engine less dependable when temperatures drop. Fix it before winter compounds the complaint.

Moderate urgency: This code often allows short-term driving, but the right fix usually comes faster when you diagnose it early instead of waiting for more codes.
Likely causes

Common causes behind this code

  • Failed cylinder 6 glow plug
  • Open or resistive feed wire to cylinder 6
  • Corroded or loose connector
  • Voltage drop from damaged harness or bus bar
  • Controller channel fault for cylinder 6

Cause phrases often tied to this code: open glow plug, damaged harness, connector corrosion, high resistance, controller driver issue.

Diagnostic order

Suggested workflow

  1. Confirm P0676 and identify the correct cylinder 6 location.
  2. Measure the glow plug resistance and compare it with the rest of the set.
  3. Check for commanded preheat voltage and excessive voltage drop at the circuit.
  4. Inspect connector fit, wiring integrity, and signs of corrosion or overheating.
  5. Repair the circuit or replace the failed part, then validate the repair on a cold start.
Avoid guesswork

Common mistakes

  • Assuming the last cylinder code automatically means the last plug is the only issue.
  • Skipping voltage-drop checks when the connector looks visually acceptable.
  • Dismissing the code because drivability seems normal after the engine warms up.
Repair path

Practical fix guidance

  • Replace the faulty cylinder 6 plug or repair the proven wiring/connector issue.
  • Inspect the shared harness and controller side if resistance patterns suggest more than one weak component.
  • Recheck crank time, startup smoke, and idle quality after a cold soak.
Vehicle context

Affected brands in this MVP

Brand hubs help broaden internal linking now and can evolve into make-specific diagnostic notes later.

Aliases and common searches

English phrases tied to P0676

Useful when the driver knows the wording but not the exact DTC yet.

  • cylinder 6 glow plug circuit
  • glow plug 6 open
  • cylinder 6 preheat fault
Related search intent

Queries this page can answer naturally

  • P0676 code meaning
  • what does P0676 mean
  • cylinder 6 glow plug symptoms
  • glow plug 6 open circuit
FAQ

Quick questions about P0676

Can P0676 be intermittent?

Yes. Marginal connectors and high resistance can make the fault appear more often during damp or colder conditions.

Does P0676 always mean the plug itself is open?

No. Wiring, connector, or controller-output faults can produce the same result at the ECU.

Why validate the repair with a cold soak?

Because the whole point of the glow plug system is cold-start support, so a warm retest does not prove the fix properly.