P0677 Fault Code

Cylinder 7 Glow Plug Circuit

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0677 code indicates a problem with the glow plug circuit for cylinder 7 in a diesel engine. The glow plug is crucial for preheating the combustion chamber, allowing for easier engine starts, especially in cold conditions. If this circuit malfunctions, it can lead to poor engine performance and difficulties in starting the vehicle.

What are the symptoms of the P0677 code?

Symptoms you might experience with a P0677 code include:

• Difficulty starting the engine, particularly in cold weather.
• Rough idling or misfires after starting.
• Reduced engine power or performance.
• Increased exhaust emissions due to incomplete combustion.

What causes the P0677 code?

The most common causes of the P0677 code include:

• A faulty glow plug in cylinder 7.
• Damaged or corroded wiring or connectors in the glow plug circuit.
• Issues with the glow plug relay.
• Problems with the Engine Control Module (ECM) affecting the glow plug operation.

How to fix P0677?

To resolve the P0677 issue, consider the following steps:

• Inspect the glow plug for cylinder 7 and replace it if it's faulty.
• Check the wiring and connectors for damage or corrosion and repair as necessary.
• Test the glow plug relay and replace it if it does not function correctly.
• Use a diagnostic scanner to clear the trouble code and test drive the vehicle to ensure the issue is resolved.