P0677 Cylinder 7 Glow Plug Circuit

OBD2 Code: P0677

Description: Cylinder 7 Glow Plug Circuit

Definition: This code indicates that there is an issue with the glow plug circuit in cylinder 7. The Engine Control Module (ECM) has detected a malfunction in the electrical circuit of the glow plug for cylinder number 7, which could be due to a faulty glow plug, wiring issues, or problems with the control module itself.

P0677 – Cylinder 7 Glow Plug Circuit

Typical Severity: Moderate

Common Causes

p0677 – Cylinder 7 Glow Plug Circuit

Common causes:

• Faulty glow plug in cylinder 7
• Wiring issues in the glow plug circuit for cylinder 7
• Loose or corroded connections related to the glow plug in cylinder 7
• Faulty glow plug control module
• Issues with the powertrain control module (PCM)

 

Common Misdiagnosis

OBD2 Code: P0677

Description: Cylinder 7 Glow Plug Circuit

Common Misdiagnosis: Replacing the glow plug without checking the wiring or control module. Often, issues with the glow plug relay or control circuit are overlooked.

 

Common Diagnostic Steps

OBD2 Code: P0677

Description: Cylinder 7 Glow Plug Circuit

• Check the glow plug for cylinder 7 for proper resistance using a multimeter.
• Inspect the wiring and connectors leading to the glow plug for damage or corrosion.
• Test the power supply to the glow plug circuit, ensuring there is voltage present when the ignition is turned on.
• Examine the glow plug control module or relay for faults or failures.
• If equipped, use an OBD2 scanner to clear the code and see if it returns after performing repairs.
• If necessary, replace the faulty glow plug with a new one that meets manufacturer specifications.