P068F 2018 Chevrolet Silverado Code - Cylinder 8 Glow Plug Control Circuit High Voltage
Quick Answer
n the diesel engine, air alone is compressed in the cylinder. Common causes include Faulty cylinder #8 glow plug, Cylinder #8 glow plug harness is open or shorted, Cylinder #8 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
- P068F 2018 Chevrolet Silverado indicates Cylinder 8 Glow Plug Control Circuit High Voltage.
- Common causes
- Common causes include Faulty cylinder #8 glow plug, Cylinder #8 glow plug harness is open or shorted, Cylinder #8 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 P068F 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 P068F 2018 Chevrolet Silverado?
- Faulty cylinder #8 glow plug
- Cylinder #8 glow plug harness is open or shorted
- Cylinder #8 glow plug circuit poor electrical connection
- Faulty Glow Plug Control Module
How to Fix the DTC P068F 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 P068F 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 P068F 2018 Chevrolet Silverado Code
What does OBDII code P068F mean on a 2018 Chevrolet Silverado?
P068F indicates an issue with the glow plug control circuit for cylinder 8, specifically that the circuit is experiencing high voltage.
What are the symptoms of the P068F code on a 2018 Chevrolet Silverado?
Symptoms may include the check engine light turning on, poor engine performance, difficulty starting in cold weather, and decreased fuel efficiency.
What causes the P068F code on a 2018 Chevrolet Silverado?
Common causes include a faulty glow plug, damaged wiring or connectors in the glow plug circuit, a defective glow plug control module, or a malfunctioning engine control module (ECM).
How is the P068F code diagnosed?
A technician will use a scan tool to verify the code, inspect the cylinder 8 glow plug and its wiring for damage, and test the glow plug control module for proper operation.
Can I continue driving with the P068F code active?
While the vehicle may still run, driving with this code can lead to poor cold-start performance and may cause additional engine strain over time. Prompt diagnosis and repair are recommended.
How do you fix the P068F code on a 2018 Chevrolet Silverado?
Repairs may include replacing the faulty glow plug for cylinder 8, repairing or replacing damaged wiring or connectors, or replacing the glow plug control module if it is defective.
Is the P068F code related to cold weather performance?
Yes, the glow plug system is essential for starting a diesel engine in cold weather, and a malfunction can cause hard starts or failure to start in low temperatures.
Can a bad battery cause the P068F code?
A weak or failing battery can cause voltage issues, but it is not a direct cause of the P068F code. However, ensuring the battery is in good condition is essential when diagnosing electrical faults.
How much does it cost to fix the P068F code on a 2018 Chevrolet Silverado?
Repair costs can vary, but replacing a glow plug typically costs $100–$300, while replacing a glow plug control module can range from $300–$600, including labor.
Can a P068F code clear itself?
The code may temporarily clear if the issue resolves itself, but it is unlikely without repairs. Even if the code disappears, the underlying problem may persist and should be addressed.
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