Engine-CodesGMC – P0673 2016 GMC Sierra

P0673 2016 GMC Sierra Code - Cylinder 3 Glow Plug Circuit Fault

Quick Answer

The diagnostic trouble code P0673 for a 2016 GMC Sierra specifically indicates a fault in the glow plug circuit of cylinder 3. Common causes include Faulty glow plug: The glow plug in cylinder 3 may be defective and require replacement, Wiring issue: A damaged or corroded wire in the glow plug circuit can prevent proper power supply to the glow plug, Glow plug relay failure: A malfunctioning glow plug relay can disrupt the power flow to the glow plug. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0673 2016 GMC Sierra indicates Cylinder 3 Glow Plug Circuit Fault.
Common causes
Common causes include Faulty glow plug: The glow plug in cylinder 3 may be defective and require replacement, Wiring issue: A damaged or corroded wire in the glow plug circuit can prevent proper power supply to the glow plug, Glow plug relay failure: A malfunctioning glow plug relay can disrupt the power flow to the glow plug.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Table of contents Created and updated by William Orellana on Sep 08, 2024
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0673 2016 GMC Sierra Description

The diagnostic trouble code P0673 for a 2016 GMC Sierra specifically indicates a fault in the glow plug circuit of cylinder 3. Glow plugs are essential components in diesel engines that help with cold starting by heating up the combustion chamber, especially in colder climates. When the engine is cold, the glow plugs heat up to ensure proper ignition of the fuel-air mixture.

OBDII Code P0673 2016 GMC Sierra - Cylinder 3 Glow Plug Circuit Fault
P0673 2016 GMC Sierra Code - Cylinder 3 Glow Plug Circuit Fault

Common Causes of P0673 2016 GMC Sierra

  1. Faulty glow plug: The glow plug in cylinder 3 may be defective and require replacement.
  2. Wiring issue: A damaged or corroded wire in the glow plug circuit can prevent proper power supply to the glow plug.
  3. Glow plug relay failure: A malfunctioning glow plug relay can disrupt the power flow to the glow plug.
  4. Control module issue: A fault in the control module that manages the glow plug circuit can trigger this diagnostic trouble code.

Symptoms of P0673 2016 GMC Sierra

  1. Hard starting: Difficulty starting the engine, especially in cold weather, can be a common symptom of a faulty glow plug in cylinder 3.
  2. Rough idle: The engine may idle roughly or unevenly due to improper combustion in the affected cylinder.
  3. Decreased fuel efficiency: A faulty glow plug can lead to incomplete combustion, resulting in decreased fuel efficiency.
  4. Check engine light: The illumination of the check engine light on the dashboard is a common indicator of an issue with the glow plug circuit.

How to Fix P0673 2016 GMC Sierra

  1. Diagnostic scan: Use an OBD-II scanner to retrieve the trouble code and confirm the issue with the glow plug circuit.
  2. Inspect wiring: Check the wiring harness for any damage, corrosion, or loose connections and repair or replace as needed.
  3. Test glow plug: Test the glow plug in cylinder 3 to determine if it is faulty and replace if necessary.
  4. Check glow plug relay: Test the glow plug relay to ensure it is functioning correctly and replace if faulty.
  5. Reset code: After completing the repairs, clear the diagnostic trouble code and test the vehicle to ensure the issue has been resolved.

Cost to Fix P0673 2016 GMC Sierra

The typical repair costs for addressing a cylinder 3 glow plug circuit fault in a 2016 GMC Sierra can vary depending on the specific cause of the issue. On average, the cost of replacing a glow plug can range from $50 to $150 per plug, while the cost of a glow plug relay can range from $50 to $100. Labor costs can vary but typically fall between $100 to $300 for this type of repair. Keep in mind that these are rough estimates, and actual costs may differ based on various factors. It's recommended to consult with a professional mechanic for a more accurate cost estimate.

Need more information about the P0673 2016 GMC Sierra code?

Need more information on how to fix the P0673 2016 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0673 2016 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0673 2016 GMC Sierra Code

No Frequently Asked Questions about P0673 2016 GMC Sierra Code found.

Discuss the causes and fixes for P0673 2016 GMC Sierra OBDII Code

Code P0673 2016 GMC Sierra comments

No comments found for this page.