What is the P0677 fault number? What is the Cylinder 7 Glow Plug Circuit/Open Malfunction description? How can I fix the fault code P0677? What are the causes and symptoms of the P0677 error code?
What is the P0677 Fault code? What does it signify?
A P0677 Code is a code that means “Cylinder 7 Glow Plug Circuit/Open . This code is set when a malfunction occurs in the cylinder 7 glowing plug circuit. Fault code 0677 will be activated if the glow plug voltage of the cylinder 7 is greater than 10% below the manufacturer set value.
Diesel vehicles have a tendency to lose the temperature of the compressed gas quickly when it is cold. This problem is solved by a glow plug (preheating element). The glow plugs are usually mounted through the cylinder heads as close to the combustion chambers as possible.
The powertrain control module (PCM) controls glow plugs. It monitors coolant and oil temperatures, transmission temperature, and intake air temperature. The PCM activates the glow plug when it detects that the engine has become cold through sensors. If code P0677 is triggered, the PCM will detect that the glow plug has not been heating up. This code usually indicates a fault in the electrical circuit and points at the glow plug of the cylinder number 7.
Glow plugs are not required when the engine heats up. 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 P0677 Fault Code?
The following are the most frequent causes of the P0677 fault code:
- – Defective glowing plug (Cylinder number 7)
- – A defective timer or control module for glow plug control
- – Defective, corroded, or damaged wires, harnesses, and any associated connectors in the glow bulb circuit
- Defective glowplug relay
- – Blown fuse
What are the symptoms for P0677 Malfunction Codes?
These symptoms may be present in vehicles with code P0677.
- Illumination of the check engine light
- – Too long waiting to start the engine
- In cold weather, the engine might not start at all
- – The Preheat light doesn’t turn on or stay on constantly
- – When the vehicle is starting, white smoke comes from the exhaust
- – You may experience a loss in power until your engine warms up.
- – Extremely loud engine noise
- Engine misfire
How to Fix the P0677 Fault Code
Diagnose this code first if you find a P0670(Glow Plug Control Module Circuit Malfunction code) along with the code.
The following repairs may be able to resolve the P0677 fault code:
- – Repair and replacement of damaged, corroded fused wires or loose connectors
- – Repair and replacement of bent or damaged pins for electrical connectors
- – Repairing open or short circuit issues and replacing blown fuses
- – Replacing the defective glow plug in cylinder 7.
- – 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 P0677 Fault Code
A code P0677 is not likely to prevent a vehicle starting. Even if one spark plug is defective, the engine will continue to run. The engine will start more difficult in colder weather, as the temperature changes and time passes. This can result in a loss of power or acceleration.
