What is the P0679 fault number? What is the Cylinder 9 glow plug circuit / open malfunction description? How can I fix the fault code P0679? What are the causes and symptoms for the P0679 fault code
What is the P0679 fault code? What does it all mean?
A P0679 code is a way to indicate that you are a professional. “Cylinder9 Glow Plug Circuit / Off” . This code is set when the PCM detects a fault in the cylinder nine glow plug circuit. Mistake code P0679 is triggered if there is more that a 10% difference between the glow plug voltage for cylinder 9 (set by the manufacturer) and the set level.
Diesel vehicles have a tendency to lose the temperature of the compressed gas quickly when it is cold. A glow plug, which is a preheating element, is used to solve this problem. The glow plugs are usually mounted through the cylinder heads as close to the combustion chambers as possible.
The powertrain control modules (PCMs) are responsible for controlling glow plugs. They monitor coolant, oil and transmission temperatures. The PCM activates the glow plug when it detects that the engine has become cold through sensors. Code P0679 is triggered if the PCM detects the glow plug not heating up. This code indicates that the electrical circuit is failing and usually points to the glow plug in cylinder 9.
When the engine is hot, however, glow plugs will not be required. To prevent damage to the engine and glow plugs, the PCM switches off the glow control system once the coolant temperature has reached a certain threshold.
What is the P0679 Fault Code and Why Does It Happen?
Fault code P0679 is most commonly triggered by the following:
- – Defective glow plug Cylinder 9
- – A defective timer or control module for glow plug control
- – In the glow plug circuit, damaged, defective, corroded wires, harnesses or associated connectors
- – A defective glow plug relay
- – Blown Fuses
What are the P0679 Malfunction Code Symptoms
You may experience the following symptoms if your vehicle has the code P0679:
- – Illumination for check engine light
- – Waiting too long before the engine starts
- In cold weather, the engine might not start at all
- – A Preheat light that does not come on or remains on at all times
- – The vehicle’s exhaust emits white smoke when it is being started
- – You may experience a loss in power until your engine warms up.
- – Extremely loud engine noise
- Engine misfire
How to Fix the P0679 Fault Code
Diagnose the code immediately if a P0670(Glow Plug Control Module Circuit Malfunction Code) is present.
The following repairs may be able to resolve the P0679 fault code:
- – Repair and replacement of damaged, corroded or fused wires, and loose connectors
- Repair or replacement of bent pins in electric connectors
- Repairing short or open circuit problems and replacing blown fuse
- – Replacing faulty glow plug 9
- – Replacing a faulty glowing plug relay
- – Replacing a defective glow plug control module, or timer
- Clear all codes, test your vehicle, and check the PCM again to make sure that there are no errors.
How Serious Is the P0679 Fault Code
A code P0679 is not likely to prevent a vehicle starting. The engine can still run if only one spark plug has failed. It is possible to make it more difficult to start the engine in colder conditions, but this can be due to time and temperature changes. This can lead to a decrease in power and acceleration.
