P0671 - Understanding DTC P0671: Commonly Seen in 2015-2018 Ford F-Series and Other Diesel Vehicles

Quick Answer

P0671 means: P0671 indicates a malfunction in the glow plug circuit for cylinder 1, affecting diesel engine performance.

Fix: Check and replace faulty components Cost: $100 - $300 Time: 90-180 minutes

Can I drive with P0671? Immediate attention is recommended to avoid starting issues and engine damage.

Common Questions

What does P0671 mean and how does it affect my car?

P0671 indicates a malfunction in the glow plug circuit for cylinder 1, primarily affecting diesel engines. This can lead to hard starts, rough idling, and decreased fuel efficiency. If left unresolved, it can result in more severe engine issues and increased emissions, thus, it is important to address it promptly.

What are the most common causes of P0671 and how much does it cost to fix?

Common causes of P0671 include a faulty glow plug, a defective glow plug relay, or wiring issues. Repair costs can range from $100 to $300 for glow plug replacements and $150 to $250 for relay replacements, depending on labor and parts required.

Can I drive my car with P0671 or should I stop immediately?

While you may still be able to drive short distances, it's not advisable to ignore P0671. Continuing to drive with this code can lead to starting difficulties and increased engine wear. It’s best to seek a diagnostic review as soon as possible to prevent further complications.

How can I diagnose P0671 myself using GeekOBD APP?

Using the GeekOBD APP, you can perform a diagnostic scan to retrieve DTCs and freeze-frame data related to the P0671 code. Follow the app's instructions to check the health of the glow plug circuit and monitor any additional related codes for a comprehensive overview.

What vehicles are most commonly affected by P0671?

Vehicles frequently affected by P0671 include 2015-2018 Ford F-Series, 2016-2020 Chevrolet Silverado 2500HD, and various models of Dodge Ram trucks. If you own these vehicles, be proactive in monitoring for symptoms related to this code.

How can I prevent P0671 from happening again?

Regular maintenance checks of your vehicle's electrical system, including the glow plug circuit, can help prevent P0671. Keeping the engine clean and avoiding contamination in the fuel system are also key preventive measures.

What is P0671?

DTC P0671 refers to a malfunction in the glow plug circuit of the engine, specifically indicating an issue with the glow plug for cylinder 1. Glow plugs are essential for starting diesel engines, especially in colder temperatures, as they heat the combustion chamber to ensure smoother ignition. When this code is triggered, it indicates that the engine control module (ECM) has detected a fault in the glow plug circuit, which could be due to a bad glow plug, a faulty relay, or wiring issues. Ignoring this code can lead to hard starting, increased emissions, and engine performance issues. Owners may experience rough idling and decreased fuel efficiency until the problem is resolved. It's crucial for diesel vehicle owners, particularly those driving models like the 2015-2018 Ford F-Series or the 2016-2020 Chevrolet Silverado 2500HD, to address this code promptly to avoid further engine complications.

System: P - Powertrain (Engine, Transmission, Emissions)

Symptoms

Common symptoms when P0671 is present:

  • The check engine light remains illuminated, indicating an ongoing issue that requires attention.
  • Engine hesitates during acceleration, resulting in sluggish performance and potential stalling in extreme cases.
  • Fuel economy decreased by 10-15%, leading to higher operational costs and reduced efficiency.
  • Rough idle can occur, especially when the engine is cold, causing discomfort and potential engine strain.
  • Difficulty starting the engine, particularly in cold weather, can lead to frustration and extended cranking times.

Possible Causes

Most common causes of P0671 (ordered by frequency):

  1. The most common cause is a faulty glow plug, which has a likelihood of about 60%. Over time, glow plugs can wear out and fail to heat adequately.
  2. A faulty glow plug relay is another common issue, occurring in about 25% of cases. This relay controls the power to the glow plugs, and if it fails, the glow plugs will not operate correctly.
  3. Wiring issues, such as damaged or corroded wires, account for about 10% of P0671 codes. Regular inspection of the wiring harness can prevent such problems.
  4. Less common, but serious, is an ECM malfunction. If the ECM is not sending the correct signals, this could lead to persistent issues with the glow plug system.
  5. A rare but possible cause is the presence of water or contamination in the fuel system, which can affect the combustion process and trigger DTC P0671.

P0671 Repair Costs

Cost Breakdown by Repair Type

Glow Plug Replacement

Replacing the faulty glow plug with a new part to restore proper function.

  • Total: $100 - $300
  • Success rate: 85%
Glow Plug Relay Replacement

Replacing the relay to ensure the glow plugs receive proper power.

  • Total: $150 - $250
  • Success rate: 75%
Money-Saving Tips for P0671
  • Start with the most common and least expensive repairs first
  • Use GeekOBD APP to confirm diagnosis before replacing expensive parts
  • Consider preventive maintenance to avoid future occurrences
  • Compare prices for OEM vs aftermarket parts based on your needs
  • Address the issue promptly to prevent more expensive secondary damage

Diagnostic Steps

Professional P0671 Diagnosis Process

Follow these systematic steps to accurately diagnose P0671. Each step builds on the previous one to ensure accurate diagnosis.

Step 1: Perform an initial visual inspection, checking for damaged wiring, loose connections, or signs of corrosion
GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 2: Use the GeekOBD APP to conduct an OBD2 scan, retrieving all codes and freeze-frame data
GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 3: Conduct component testing using a multimeter to check the resistance of the glow plug and the relay
GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 4: After repairs, conduct a system function test to verify proper operation and clear any stored codes
GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.
Step 5: Finally, perform a road test under various conditions to confirm repair success
GeekOBD APP Tip: Use GeekOBD APP to monitor real-time data during this diagnostic step for accurate results and professional-grade analysis.

Important Notes

  • Always verify the repair with GeekOBD APP after completing diagnostic steps
  • Clear codes and test drive to ensure the problem is resolved
  • Address underlying causes to prevent code recurrence

Real Repair Case Studies

Case Study 1: Glow Plug Replacement on a 2016 Ford F-250

Vehicle: 2016 Ford F-250, 75,000 miles

Problem: Customer reported difficulty starting the vehicle, especially in cold weather, and the check engine light was on.

Diagnosis: After running an OBD2 scan with the GeekOBD APP, the P0671 code was retrieved, indicating a glow plug issue. Visual inspection revealed corrosion on the wiring harness.

Solution: Replaced the faulty glow plug and cleaned the wiring connections. The relay was also tested and found to be functional.

Cost: $220 (parts and labor)

Result: The vehicle started smoothly after repairs, and the check engine light was cleared.

Case Study 2: Glow Plug Relay Replacement on a 2017 Chevrolet Silverado 2500HD

Vehicle: 2017 Chevrolet Silverado 2500HD, 60,000 miles

Problem: Customer experienced rough idling and reduced fuel efficiency, with a persistent check engine light.

Diagnosis: OBD2 scan indicated a P0671 code. Upon inspection, the glow plug relay was found to be malfunctioning.

Solution: Replaced the glow plug relay and performed a system check to ensure all components were functioning correctly.

Cost: $180 (parts and labor)

Result: Post-repair, the engine ran smoothly, and fuel efficiency improved.

Diagnose P0671

Use GeekOBD APP for professional diagnosis!

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  • Step-by-step repair guidance
  • Professional-grade analysis
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Code Information

Code: P0671
System: Powertrain (Engine, Transmission, Emissions)
Severity: HIGH
Category: Engine Codes