P0674 2018 Chevrolet Silverado Code - Cylinder 4 Glow Plug Circuit Fault
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #4 glow plug, Cylinder #4 glow plug harness is open or shorted, Cylinder #4 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
- P0674 2018 Chevrolet Silverado indicates Cylinder 4 Glow Plug Circuit Fault.
- Common causes
- Common causes include Faulty cylinder #4 glow plug, Cylinder #4 glow plug harness is open or shorted, Cylinder #4 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 P0674 2018 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 P0674 2018 Chevrolet Silverado?
- Faulty cylinder #4 glow plug
- Cylinder #4 glow plug harness is open or shorted
- Cylinder #4 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module (GPCM)
How to Fix the DTC P0674 2018 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 P0674 2018 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 P0674 2018 Chevrolet Silverado Code
1. What does the OBDII code P0674 mean on a 2018 Chevrolet Silverado?
P0674 indicates a fault in the glow plug circuit for cylinder 4, which may impact the engine's ability to start or run efficiently in cold conditions.
2. What are the symptoms of code P0674 in a 2018 Chevrolet Silverado?
Common symptoms include difficulty starting the engine in cold weather, rough idle, reduced fuel efficiency, and the illumination of the check engine light.
3. What causes the P0674 code to appear in a 2018 Chevrolet Silverado?
Possible causes include a faulty glow plug in cylinder 4, damaged wiring or connectors in the glow plug circuit, a malfunctioning glow plug control module, or a blown fuse.
4. How can I diagnose the P0674 code on my Chevrolet Silverado?
Start by inspecting the glow plug for cylinder 4, checking for physical damage or excessive wear. Next, inspect the wiring and connectors in the circuit for corrosion, damage, or loose connections. Use a multimeter to test the glow plug's resistance and the circuit's continuity.
5. Can I drive my 2018 Chevrolet Silverado with a P0674 code?
While the truck may still run, driving with this code can lead to hard starts in cold weather and potential long-term damage if the issue is not addressed.
6. How do I fix the P0674 code on a 2018 Chevrolet Silverado?
Repairs may include replacing the faulty glow plug for cylinder 4, repairing or replacing damaged wiring or connectors, or replacing the glow plug control module if it's faulty.
7. How much does it cost to fix the P0674 code on a Chevrolet Silverado?
The cost can vary, but replacing a glow plug typically ranges from $50 to $150 for parts and labor. If additional repairs are needed (e.g., wiring or control module), costs may increase.
8. Can a bad glow plug cause other issues in my 2018 Chevrolet Silverado?
Yes, a bad glow plug can lead to poor cold starts, increased emissions, and reduced engine performance over time.
9. How do I prevent the P0674 code from appearing again?
Regular maintenance, including inspecting and replacing glow plugs as needed, and ensuring the wiring and connectors are clean and intact, can help prevent this issue.
10. Do I need special tools to fix the P0674 code on my Chevrolet Silverado?
Basic tools like a socket wrench and multimeter are often sufficient for diagnosing and replacing a glow plug. However, more advanced diagnostic tools, such as an OBDII scanner, may be needed to clear the code after repairs.
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