AutoCodesChevrolet – P0677 2017 Chevrolet Silverado

P0677 2017 Chevrolet Silverado Code - Cylinder 7 Glow Plug Circuit Fault

Quick Answer

n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #7 glow plug, Cylinder #7 glow plug harness is open or shorted, Cylinder #7 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
P0677 2017 Chevrolet Silverado indicates Cylinder 7 Glow Plug Circuit Fault.
Common causes
Common causes include Faulty cylinder #7 glow plug, Cylinder #7 glow plug harness is open or shorted, Cylinder #7 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.
AI answers can be wrong. Verify repairs with testing. Open full chat
Code Popularity 340
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Mar 24, 2024
💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0677 2017 Chevrolet Silverado 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 P0677 2017 Chevrolet Silverado - Cylinder 7 Glow Plug Circuit Fault - AutoCodes.com
P0677 2017 Chevrolet Silverado Code - Cylinder 7 Glow Plug Circuit Fault

What are the Possible Causes of the DTC P0677 2017 Chevrolet Silverado?

  • Faulty cylinder #7 glow plug
  • Cylinder #7 glow plug harness is open or shorted
  • Cylinder #7 glow plug circuit poor electrical connection
  • Faulty Glow Plug Control Module (GPCM)

How to Fix the DTC P0677 2017 Chevrolet Silverado?

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 P0677 2017 Chevrolet Silverado 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 P0677 2017 Chevrolet Silverado code?

Need more information on how to fix the P0677 2017 Chevrolet Silverado code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0677 2017 Chevrolet Silverado 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 P0677 2017 Chevrolet Silverado Code

What does OBDII code P0677 mean on a 2017 Chevrolet Silverado?

P0677 indicates a Cylinder 7 Glow Plug Circuit Fault, meaning the glow plug or associated wiring for cylinder 7 is malfunctioning.

What are the symptoms of code P0677 in a 2017 Silverado?

Common symptoms include hard starting in cold weather, rough idle, reduced engine performance, and the check engine light illuminating.

What causes code P0677 to appear on a Chevrolet Silverado?

The code can be caused by a faulty glow plug, damaged wiring or connectors, a bad glow plug control module, or corrosion in the circuit.

Can I drive my 2017 Silverado with code P0677?

It may be possible to drive the vehicle, but starting and performance issues in cold weather could worsen. Prompt diagnosis and repair are recommended.

How do I diagnose code P0677 on my Silverado?

Check the glow plug for cylinder 7, inspect the wiring and connectors for damage or corrosion, and test the glow plug control module for proper operation.

How do I fix code P0677 on a 2017 Chevrolet Silverado?

Repairs typically involve replacing the faulty glow plug for cylinder 7, repairing damaged wiring, or replacing the glow plug control module if needed.

What tools are needed to fix code P0677?

You may need a scan tool, a digital multimeter, and basic hand tools to test and replace the faulty components.

How much does it cost to repair P0677 on a Silverado?

Repair costs vary but typically range from $150 to $300, depending on whether you need a glow plug replacement or additional wiring repairs.

Can a bad glow plug in cylinder 7 affect fuel efficiency?

Yes, a malfunctioning glow plug can cause incomplete combustion, potentially reducing fuel efficiency and engine performance.

How can I prevent code P0677 from reoccurring?

Regularly inspect the glow plug system, ensure proper maintenance, and address any wiring or corrosion issues promptly.

Discuss the causes and fixes for P0677 2017 Chevrolet Silverado OBDII Code

Code P0677 2017 Chevrolet Silverado comments

No comments found for this page.

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