The P0679 OBD-II trouble code is associated with the glow plug circuit for cylinder 9 in diesel engines. This code indicates a fault in the glow plug circuit that may prevent proper operation, which can lead to significant issues during engine start-up, especially in cold conditions.
What Does the P0679 Code Mean?
When the engine control module (PCM) detects that the glow plug for cylinder 9 is not functioning correctly, it triggers the P0679 code. This is particularly important for diesel engines, as glow plugs are essential for preheating the cylinders before starting the engine.
What Causes the P0679 Code?
- Glow plug control module failure
- Glow plug failure
- Glow plug wiring harness failure
What Are the Symptoms of the P0679 Code?
- Engine may not start
- Hard or no start in cold weather
How Serious Is the P0679 Code?
The P0679 code is considered urgent. It indicates that immediate action is necessary to prevent severe engine damage or to ensure the safety of the driver and passengers. Ignoring this code can lead to further complications, especially in cold weather conditions.
How to Diagnose the P0679 Code
Diagnosing the P0679 code involves a complete diagnostic routine. A mechanic will typically:
- Check the OBD-II system for additional codes.
- Inspect the glow plug wiring harness for any visible damage.
- Test the glow plug control module.
- Check the operation of the glow plug itself.
Common Repairs for the P0679 Code
- Glow Plug Replacement
- Repair or replace the glow plug control module
- Repair wiring harness issues
How Much Does It Cost to Fix the P0679 Code?
The cost to fix the P0679 code can vary widely depending on the specific issue. Typically, glow plug replacement can range from $100 to $300, while repairs to wiring or the control module may increase costs further. It’s advisable to get a detailed quote from a professional mechanic.
Can I Fix the P0679 Code Myself?
If you have automotive knowledge and experience, you might be able to diagnose and fix the P0679 code yourself. However, it is crucial to approach this with caution. Proper diagnosis is essential, and sometimes the underlying issue may not be obvious. If unsure, it is best to consult a professional mechanic to avoid unnecessary repairs.
