P0679 Code - Cylinder 9 Glow Plug Circuit Fault
Quick Answer
The diagnostic trouble code P0679 indicates a fault in the cylinder 9 glow plug circuit in a diesel engine. Common causes include Faulty glow plug in cylinder 9, Damaged wiring or connectors in the glow plug circuit, Blown fuse related to the glow plug circuit. 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
- P0679 indicates Cylinder 9 Glow Plug Circuit Fault.
- Common causes
- Common causes include Faulty glow plug in cylinder 9, Damaged wiring or connectors in the glow plug circuit, Blown fuse related to the glow plug circuit.
- 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 P0679 Description
The diagnostic trouble code P0679 indicates a fault in the cylinder 9 glow plug circuit in a diesel engine. Glow plugs are crucial components in diesel engines, especially during cold starts, as they heat the combustion chamber to facilitate ignition. When a glow plug circuit fault occurs in cylinder 9, it means that there is an issue with the electrical system responsible for heating the glow plug in that specific cylinder.
Common Causes of P0679
- Faulty glow plug in cylinder 9.
- Damaged wiring or connectors in the glow plug circuit.
- Blown fuse related to the glow plug circuit.
- Malfunctioning glow plug relay.
- ECM issue affecting the glow plug circuit.
Symptoms of P0679
- Difficulty starting the engine, especially in cold weather.
- Rough idling or misfires.
- Reduced engine performance and power.
- Increased exhaust smoke.
- Illumination of the check engine light.
How to Fix P0679
- Diagnose the specific cause of the fault using a scan tool to identify the faulty component.
- Inspect and test the glow plug in cylinder 9 to determine if it needs replacement.
- Check the wiring and connectors for damage and repair or replace as necessary.
- Test the glow plug relay and replace it if it is malfunctioning.
- Clear the trouble code from the ECM and perform a test start to ensure the issue is resolved.
Cost to Fix P0679
The typical repair costs for addressing a cylinder 9 glow plug circuit fault can range from $100 to $300, including parts and labor. However, actual costs may vary based on the specific diagnosis time, labor rates, and the price of replacement components. It is advisable to consult with a trusted mechanic or auto repair shop for an accurate estimate based on the vehicle's make and model, as well as the severity of the issue.
When is the Code Detected?
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Code P0679 Information for Specific Makes
- P0679 Volkswagen — Cylinder 9 Glow Plug Circuit Fault
Frequently Asked Questions about P0679 Code
1. What are common symptoms of OBDII code P0679 (Cylinder 9 Glow Plug Circuit Fault)?
- Common symptoms include hard starting, rough idling, decreased fuel efficiency, and the illumination of the check engine light.
2. What are possible causes of OBDII code P0679?
- Possible causes include a faulty glow plug in cylinder 9, damaged wiring or connectors in the glow plug circuit, or a malfunctioning glow plug control module.
3. How can I diagnose the cause of OBDII code P0679?
- Diagnosing the issue involves using a multimeter to test the resistance of the glow plug, inspecting the wiring for damage, and checking the glow plug control module for proper functioning.
4. Can I still drive my vehicle with OBDII code P0679?
- It is not recommended to drive the vehicle with this code as it can lead to poor engine performance and potential damage over time. It is best to address the issue promptly.
5. What are the repair options for OBDII code P0679?
- Repair options include replacing the faulty glow plug in cylinder 9, repairing any damaged wiring or connectors, or replacing the glow plug control module if necessary.
6. Are there any preventive maintenance tips to avoid OBDII code P0679 in the future?
- Regularly inspecting and testing the glow plugs in all cylinders, ensuring proper maintenance of the glow plug circuit components, and using high-quality diesel fuel can help prevent this issue.
7. Can weather conditions affect the occurrence of OBDII code P0679?
- Yes, extreme cold weather can put more strain on the glow plug system, potentially leading to issues like cylinder 9 glow plug circuit faults. Properly functioning glow plugs are crucial in cold climates.
8. How long does it typically take to repair OBDII code P0679?
- The repair time can vary depending on the exact cause of the issue and the extent of the repairs needed. On average, it may take a few hours to a full day for a mechanic to address the problem.
9. Can OBDII code P0679 affect the overall performance of my vehicle?
- Yes, if left unresolved, OBDII code P0679 can impact the performance of your vehicle, leading to issues such as reduced power, increased emissions, and potential engine damage.
10. Is it necessary to clear the OBDII code P0679 after the repairs are completed?
- Yes, it is important to clear the code using an OBDII scanner after the repairs to reset the system and ensure the issue has been successfully addressed.
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