DTC P0277 Cylinder 6 Injector Circuit High

As a car owner who takes pride in maintaining your vehicle’s performance, it’s important to be aware of potential issues that can arise. DTC P0277, specifically related to “Cylinder 6 Injector Circuit High,” is a concern that can disrupt the balance of fuel delivery to Cylinder 6 in your engine. In this comprehensive guide, we will delve into the causes, symptoms, inspection methods, resolutions, and the process of clearing DTC P0277. With this knowledge, you can confidently address the issue and ensure your engine operates at its best.

Causes of DTC P0277:

DTC P0277 occurs when the engine control module detects a high voltage signal in the injector circuit of Cylinder 6. Several factors can contribute to this issue:

  • Faulty Injector: A malfunctioning injector in Cylinder 6 can lead to excessive fuel delivery.
  • Wiring Issues: Damaged or corroded wiring can result in unintended high voltage readings.
  • Poor Connections: Loose or poor connections in the injector circuit can lead to erratic voltage readings.
  • Faulty Engine Control Module (ECM): An issue with the ECM responsible for controlling fuel injection can cause high voltage.

2. Symptoms of DTC P0277:

Recognizing potential symptoms can help you identify the issue promptly:

  • Engine Misfires: Cylinder 6 might experience intermittent misfires or hesitation due to excessive fuel delivery.
  • Rough Idling: The engine might exhibit rough idling or vibration, particularly when Cylinder 6 is affected.
  • Reduced Power: Your vehicle’s overall power and performance might decrease due to excessive fuel delivery to Cylinder 6.

3. Inspection of DTC P0277:

Conducting a thorough inspection is essential for accurate diagnosis of the high voltage issue:

  • Visual Examination: Inspect the wiring and connectors of Cylinder 6’s injector for any damage or corrosion.
  • Injector Testing: Test the performance of the injector in Cylinder 6 to ensure proper fuel delivery.
  • Wiring Check: Inspect the injector circuit wiring for any damage, corrosion, or loose connections.
  • ECM Check: Evaluate the ECM’s functionality to ensure it’s properly controlling fuel injection.

4. Resolving Causes of DTC P0277:

Based on your inspection, take these steps to address the high voltage issue:

  • Replace Faulty Injector: If the injector in Cylinder 6 is faulty and causing excessive fuel delivery, replace it with a compatible replacement.
  • Repair Wiring and Connections: Fix any damaged wiring or connectors in the injector circuit.
  • Ensure Proper Connections: Ensure all connections in the injector circuit are secure and properly seated.
  • ECM Replacement: If the ECM is found to be faulty and causing the high voltage issue, consider replacing it with a compatible unit.

5. Clearing DTC P0277:

After resolving the root cause of the high voltage issue, clear the code and reset the check engine light:

  • OBD-II Scanner: Use an OBD-II scanner to clear the code and turn off the check engine light.
  • Test Drive: Take the vehicle for a test drive to confirm that the issue has been resolved and the light remains off.


By addressing issues like DTC P0277, you demonstrate your dedication to maintaining your vehicle’s performance. Staying informed about potential problems contributes to the longevity and efficiency of your vehicle. Responsible car ownership involves both enjoying the driving experience and ensuring the health of your engine’s components. This guide is here to support every step of your journey as a car owner, even when dealing with injector circuit high issues in specific cylinders.