The engine fault code P0679 refers to an issue with the glow plug circuit for cylinder 9. Glow plugs are used in diesel engines to help start the engine by heating the air in the combustion chamber. If the code indicates a `circuit/open,` it usually means there is a problem with the electrical circuit related to the glow plug for that cylinder. This could be due to a faulty glow plug, a bad connection, or an issue with the wiring.
Alternative Meanings by Manufacturer:
1. Volkswagen/Audi: Similar to the general definition, it often indicates a problem with the glow plug circuit specifically for cylinder 9 in their diesel engines.
2. Mercedes-Benz: The code may refer to a malfunction in the glow plug system, but it could also indicate issues with the engine control unit (ECU) or related sensors.
3. Jaguar/Land Rover: The same definition applies, but it might also trigger other codes due to the integrated systems in these vehicles.
4. Porsche: While P0679 is less common in Porsches, if it occurs, it would generally mean the same issue with the glow plug circuit.
Our view, regardless of the manufacturer, the code points to an issue with the glow plug system for cylinder 9. If you encounter this code, its a good idea to check the glow plug, wiring, and connectors for any faults.
The Engine Fault Code P0679 indicates a problem with the glow plug circuit for cylinder 9. This code is typically associated with diesel engines, where glow plugs are used to help start the engine in cold conditions. Here are some common causes for this code, which can vary slightly depending on the manufacturer:
1. Faulty Glow Plug: The glow plug for cylinder 9 may be defective or burned out, preventing it from heating properly.
2. Wiring Issues: There could be damaged or corroded wiring in the glow plug circuit. This includes broken wires, loose connections, or poor grounding.
3. Faulty Glow Plug Relay: The relay that controls power to the glow plugs might be malfunctioning, which can prevent the glow plug from receiving the necessary voltage.
4. ECM Issues: The Engine Control Module (ECM) could have a fault that affects its ability to monitor or control the glow plug circuit for cylinder 9.
5. Short Circuit: There may be a short circuit in the glow plug circuit, which can lead to incorrect readings and trigger the fault code.
6. Faulty Sensor: In some cases, a faulty temperature sensor can send incorrect signals to the ECM, leading to issues with the glow plug operation.
Manufacturer-Specific Considerations:
– Porsche: While Porsche primarily uses gasoline engines, in models with diesel engines, the same issues apply. Additionally, the coding might be more integrated with the vehicle`s advanced electronics.
– Mini: Similar to BMW, Mini models with diesel engines may show this code. Look for common issues with the wiring harness, as they can be prone to wear.
– Mercedes: Mercedes models often have more complex glow plug systems. Check for specific software updates or recalls that might affect the glow plug operation.
– Audi: Audi vehicles may have more sophisticated diagnostics. A scan tool may provide additional codes that can help pinpoint the issue more accurately.
– Jaguar: Jaguar`s diesel engines can have unique wiring layouts, so checking the specific wiring diagrams for that model is essential.
– Land Rover: Land Rover vehicles may also have additional layers of control for the glow plugs, so checking for software updates is crucial.
Conclusion
If you encounter the P0679 code, it`s best to start with a thorough inspection of the glow plug, wiring, and relay. Using a diagnostic tool can help identify additional codes or issues that may be related. Always consult the specific service manual for your vehicle to ensure you follow the correct troubleshooting steps.
The P0679 code indicates a problem with the glow plug circuit for cylinder 9. This code is commonly found in diesel engines, particularly in vehicles that use glow plugs to help start the engine. Heres a general approach to fixing this issue, but keep in mind that specifics can vary by manufacturer.
General Steps to Fix P0679:
1. Check the Owners Manual: Always start by looking at the vehicles manual. It may provide specific troubleshooting steps or wiring diagrams.
2. Visual Inspection:
– Inspect the glow plug for cylinder 9. Look for signs of damage, corrosion, or wear.
– Check the wiring and connectors leading to the glow plug. Look for frayed wires or loose connections.
3. Test the Glow Plug:
– Use a multimeter to test the resistance of the glow plug. Typically, a good glow plug will have a resistance of 0.5 to 5 ohms. If its out of this range, replace it.
4. Check the Glow Plug Relay:
– The glow plug relay controls power to the glow plugs. Test the relay to ensure its functioning correctly. If its faulty, replace it.
5. Inspect the Fuse:
– Check the fuse related to the glow plug circuit. If its blown, replace it and see if the code clears.
6. Scan for Other Codes:
– Use an OBD-II scanner to check for other related trouble codes. Sometimes, multiple codes can point to a bigger issue.
7. Clear the Codes:
– After making repairs, clear the codes with the scanner and take the vehicle for a test drive to see if the code returns.
Manufacturer-Specific Notes:
– Volkswagen/Audi: These vehicles often have more complex glow plug systems. If youre dealing with a TDI engine, consider checking the Engine Control Unit (ECU) for updates or faults.
– Mercedes-Benz: Some models may have a glow plug control module. If the glow plugs and relay are fine, you may need to check this module.
– Porsche: If youre working on a Cayenne or Macan with a diesel engine, the approach is similar to Audi, as they share many components.
– Land Rover/Jaguar: These vehicles may have unique wiring harnesses. Ensure you check for any recalls or service bulletins related to glow plug issues.
– Mini: If its a diesel Mini, the process is similar to BMW, as they share engine components. Look for common issues with the glow plug control.
Final Thoughts:
If youre not comfortable performing these tests or repairs, its best to consult a professional mechanic. Glow plug systems can be tricky, and getting it wrong might lead to further issues. Always prioritize safety and ensure the vehicle is off and cool before working on it.
Driving with a P0679 code, which indicates a problem with the glow plug circuit for cylinder 9, generally isn`t safe, especially in diesel vehicles. Glow plugs help start the engine by heating the air in the combustion chamber. If there`s an issue, it can lead to hard starting or even engine misfires.
Heres a breakdown by manufacturer:
1. Porsche:
– Most Porsches are gasoline engines, so this code might not apply. If it does, it could indicate a serious issue, and you should avoid driving until it`s fixed.
2. Mini:
– Mini diesel models may have this issue. It can lead to starting problems, so it`s best not to drive until you fix it.
3. Mercedes:
– In Mercedes diesel engines, a P0679 can lead to rough starts or poor performance. Driving might be possible but not recommended. Get it checked out soon.
4. Audi:
– Similar to Mercedes, Audi diesels may experience issues with starting and performance. Its safer to have it repaired before driving.
5. Jaguar:
– Jaguar diesel engines can also be affected. If you see this code, its advisable to get it fixed to avoid starting issues.
6. Land Rover:
– Land Rover diesel vehicles may have similar problems. Its best to address the code before driving to ensure reliability.
General Advice:
– Immediate Attention: If you see this code, it`s best to have it checked out. Ignoring it can lead to more significant issues.
– Driving Conditions: If you must drive, do so cautiously and be prepared for possible starting issues.
– Professional Help: Always consult a professional mechanic for a proper diagnosis and repair.
Our take, while you may be able to drive with a P0679 code, it`s not advisable. Fixing the issue sooner rather than later is the best course of action.
