P0677 2015 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 2015 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.
Code P0677 2015 Chevrolet Silverado Description
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.
What are the Possible Causes of the DTC P0677 2015 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 2015 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 2015 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.
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Frequently Asked Questions about P0677 2015 Chevrolet Silverado Code
What does OBD-II code P0677 mean in a 2015 Chevrolet Silverado?
Code P0677 indicates a fault in the glow plug circuit for cylinder 7, which may affect the engine's ability to start in cold conditions.
What are the symptoms of code P0677 in a 2015 Chevrolet Silverado?
Symptoms may include difficulty starting the engine in cold weather, rough idling, and the check engine light turning on.
What causes code P0677 in a 2015 Chevrolet Silverado?
Common causes include a failed glow plug in cylinder 7, a damaged glow plug control module, wiring issues such as corrosion or breaks, or a faulty electrical connector.
How do I diagnose code P0677 in a 2015 Chevrolet Silverado?
Start by inspecting the glow plug in cylinder 7, checking for physical damage or wear, and testing its resistance. Also, inspect wiring and connectors for corrosion or damage.
Is it safe to drive with code P0677 in a 2015 Chevrolet Silverado?
While the vehicle may still be drivable, it may experience difficulty starting in cold weather and reduced efficiency. Prompt repair is recommended to avoid further damage.
Can code P0677 cause engine damage in a 2015 Chevrolet Silverado?
While it may not directly cause engine damage, prolonged issues with the glow plug circuit can lead to harder starts and increased wear on engine components over time.
How do I fix code P0677 in a 2015 Chevrolet Silverado?
Repairs may involve replacing the glow plug for cylinder 7, repairing damaged wiring or connectors, or replacing the glow plug control module if faulty.
How much does it cost to repair code P0677 in a 2015 Chevrolet Silverado?
The cost varies depending on the exact issue but may range from $50 to $300, with glow plug replacements being on the lower end and module replacement on the higher end.
Can extreme weather conditions cause code P0677 in a 2015 Chevrolet Silverado?
Yes, extreme cold can exacerbate existing issues with the glow plug circuit, making it more likely for the code to appear.
How can I prevent code P0677 from occurring in a 2015 Chevrolet Silverado?
Regular maintenance, including inspecting glow plugs, wiring, and connectors for wear or corrosion, can help prevent this code from appearing.
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