Ford Power Stroke · Glow Plug Cylinder 1Medium

Ford Power Stroke P0671: Glow Plug Cylinder 1 Diagnosis

P-code P0671 (FMI N/A) — Cylinder 1 Glow Plug Circuit/Open

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Quick Answer

On Ford Power Stroke, P0671 means Cylinder 1 Glow Plug Circuit/Open. Prove the system with live data on FORScan before replacing parts.

Overview: Ford Power Stroke P-code P0671

On Ford Power Stroke, P0671 means Cylinder 1 Glow Plug Circuit/Open. Prove the system with live data on FORScan before replacing parts. This page covers symptoms, causes, tests, and common misdiagnoses.

Repair Snapshot

Time

1 - 3 Hours

Difficulty

Intermediate

Parts Cost

$40 - $1,200

Dealer Labor

$300+

Tools Required

  • FORScan
  • Ford FDRS/IDS
  • Multimeter

What P-code P0671 Means

P0671 on Ford Power Stroke reports Cylinder 1 Glow Plug Circuit/Open. Typical root causes include wiring faults, sensor rationality issues, and mechanical problems in the electrical path. Use FORScan / Ford FDRS/IDS to confirm before a parts cannon.

Symptoms Drivers Notice

  • Malfunction indicator lamp illuminated
  • Power loss, rough running, or limp mode under load
  • Related aftertreatment or fuel-system complaints depending on code family
  • Code returns after clearing if root cause remains

Most Likely Root Causes

Common Misdiagnoses (Don't Waste Parts)

Why it happens:

Do this instead:

Why it happens:

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Why it happens:

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Master Tech Commentary

Mechanic's Notes

Shop tip (Ford Power Stroke P0671): Do not quote the expensive assembly from the code name alone. Confirm live data rationality and wiring first.

Step-by-Step Diagnostic Procedure

  1. Step 1: Scan with FORScan and save freeze-frame for P0671.
  2. Step 2: Inspect connectors and harness for the glow plug cylinder 1.
  3. Step 3: Compare PID values to mechanical gauges or known-good ranges.
  4. Step 4: Repair the proven fault, then verify with a loaded drive cycle.

Live Data & Freeze-Frame Tips

Log the PIDs tied to P0671 under freeze-frame load with FORScan. Compare commanded vs actual values.

When to Limp In vs Tow

Drive carefully if power remains controllable; tow if limp mode is severe.

Related Fault Codes

Frequently Asked Questions

What does P0671 mean on Ford Power Stroke?

Cylinder 1 Glow Plug Circuit/Open. Confirm with live data before replacing parts.

Can I drive with P0671?

Short trips may be possible, but continued hard pulls risk limp mode or aftertreatment damage. Diagnose promptly.

What tools should I use?

FORScan, Ford FDRS/IDS, Multimeter.

Should I clear the code first?

No — save freeze-frame and repair first.

More Ford Power Stroke codes on this system

All Ford Power Stroke fault codes

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