AutoCodes – GMC – P0676 2018 GMC Sierra

P0676 2018 GMC Sierra Code - Cylinder 6 Glow Plug Circuit Fault

Quick Answer

n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #6 glow plug, Cylinder #6 glow plug harness is open or shorted, Cylinder #6 glow plug circuit poor electrical connection. 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: P0676 2018 GMC Sierra indicates Cylinder 6 Glow Plug Circuit Fault.
Common causes: Common causes include Faulty cylinder #6 glow plug, Cylinder #6 glow plug harness is open or shorted, Cylinder #6 glow plug circuit poor electrical connection.
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.

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Code Popularity 168

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 24, 2024

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0676 2018 GMC Sierra Description

n the diesel engine, air alone is compressed in the cylinder. Then, after the air has been compressed, a charge of fuel is sprayed into the cylinder and ignition occurs, due to the heat of compression. Eight glow plugs are used as an aid to starting.
Control of the glow plugs is accomplished by the Glow Plug Control Module. The nominal voltage for the glow plugs is 5.4 volts. When the ignition is turned On, the Glow Plug Control Module applies 7.2 V for 2.2 s, then 5.7 V for 0.8 s, and then 5.4 V until 1200°C (2192°F) is reached. The maximum voltage of the system is 10 V. While the engine is running the voltage will vary between 4.7 - 10 V when in closed loop control to maintain a glow plug temperature that ranges from 1150° - 1180°C (2102° - 2156°F). The temperature and the power consumption are controlled between the Engine Control Module (ECM) and the Glow Plug Control Module within a wide range to suit the engine's pre-heating requirements. Each glow plug is energized individually. This capability yields more optimum heat times for the glow plugs, thus pre - glow times can be kept to a minimum for a short wait to crank times and maximum glow plug durability.

OBDII Code P0676 2018 GMC Sierra - Cylinder 6 Glow Plug Circuit Fault - AutoCodes.com — P0676 2018 GMC Sierra Code - Cylinder 6 Glow Plug Circuit Fault

What does this mean?

What are the Possible Causes of the DTC P0676 2018 GMC Sierra?

Faulty cylinder #6 glow plug
Cylinder #6 glow plug harness is open or shorted
Cylinder #6 glow plug circuit poor electrical connection
Faulty Glow Plug Control Module (GPCM)

How to Fix the DTC P0676 2018 GMC Sierra?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0676 2018 GMC Sierra code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0676 2018 GMC Sierra code?

Need more information on how to fix the P0676 2018 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

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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 P0676 2018 GMC Sierra Code

1. What are the common symptoms of OBDII code P0676 on a 2018 GMC Sierra?

The common symptoms of OBDII code P0676, which indicates a Cylinder 6 Glow Plug Circuit Fault, include rough idling, engine misfires, decreased fuel efficiency, and the illumination of the Check Engine Light.

2. What are the possible causes of OBDII code P0676 on a 2018 GMC Sierra?

Possible causes of OBDII code P0676 in a 2018 GMC Sierra include a faulty glow plug in cylinder 6, damaged wiring or connectors in the glow plug circuit, a defective glow plug control module, or issues with the powertrain control module.

3. How can I diagnose the Cylinder 6 Glow Plug Circuit Fault on my 2018 GMC Sierra?

Diagnosing OBDII code P0676 involves using a scan tool to retrieve the specific fault code, inspecting the glow plug in cylinder 6 for damage, checking the wiring and connectors for any signs of wear or corrosion, and testing the glow plug control module for proper functioning.

4. Can I continue driving my 2018 GMC Sierra with OBDII code P0676?

It is not recommended to continue driving your 2018 GMC Sierra with OBDII code P0676, as the issue can lead to further engine damage and reduced performance. It is best to address the Cylinder 6 Glow Plug Circuit Fault as soon as possible.

5. How can I repair OBDII code P0676 on my 2018 GMC Sierra?

To repair OBDII code P0676 on a 2018 GMC Sierra, you may need to replace the faulty glow plug in cylinder 6, repair or replace damaged wiring and connectors, replace the glow plug control module if necessary, and clear the fault code with a scan tool.

6. Is it possible to prevent OBDII code P0676 from occurring in the future?

While some causes of OBDII code P0676 may be unavoidable, regular maintenance of the glow plug system in your 2018 GMC Sierra can help prevent issues. Checking and replacing glow plugs as needed, inspecting wiring for damage, and keeping the system clean can help prevent future faults.

7. Can a DIY enthusiast fix OBDII code P0676 on a 2018 GMC Sierra?

Depending on your skill level and access to tools, you may be able to address OBDII code P0676 on your 2018 GMC Sierra as a DIY project. However, if you are unsure about diagnosing or repairing the issue, it is recommended to seek professional help to avoid causing further damage.

8. How long does it typically take to repair OBDII code P0676 on a 2018 GMC Sierra?

The time needed to repair OBDII code P0676 on a 2018 GMC Sierra can vary depending on the extent of the issue and the availability of parts. In general, the repair process can take anywhere from a few hours to a full day.

9. Are there any recalls or technical service bulletins related to OBDII code P0676 on a 2018 GMC Sierra?

It is advisable to check with your local GMC dealership or visit the manufacturer's official website to see if there are any recalls or technical service bulletins related to OBDII code P0676 and the Cylinder 6 Glow Plug Circuit Fault in a 2018 GMC Sierra.

10. What is the cost of repairing OBDII code P0676 on a 2018 GMC Sierra?

The cost of repairing OBDII code P0676 on a 2018 GMC Sierra can vary based on the specific problem causing the fault, the labor rates of the repair shop, and the cost of parts needed for the repair. It is recommended to obtain quotes from multiple sources to compare prices before proceeding with the repair.