P0277 Cylinder 6 Injector Circuit Low

How to Troubleshoot and Fix a Cylinder 6 Injector Circuit Low Code

If you own a modern vehicle with an electronic fuel injection system, you may encounter a diagnostic trouble code (DTC) that indicates a problem with one of the fuel injectors. One common code is P0277, which means that the engine control module (ECM) has detected a low voltage or resistance condition in the circuit that controls the fuel injector for cylinder 6. In this article, we will explain what this code means, what can cause it, and how to diagnose and repair it properly.

Introduction: What is a fuel injector and why is it important?

Before we dive into the details of the P0277 code, let’s review some basics about fuel injectors and their role in the fuel system. A fuel injector is an electromechanical device that sprays a precise amount of fuel into the combustion chamber of an engine, based on signals from the ECM. The fuel injector is responsible for delivering the right amount of fuel at the right time, to achieve optimal performance, efficiency, and emissions. A malfunctioning fuel injector can cause various symptoms, such as rough idle, misfire, loss of power, hard starting, or poor fuel economy.

What does the P0277 code mean?

The P0277 code is a generic OBD-II code that indicates a fault in the circuit that controls the fuel injector for cylinder 6. In most cases, the code is set when the ECM detects a low voltage or resistance condition in the circuit, which can be caused by a short or open circuit, a faulty injector, a damaged wire, a loose connection, or a failed ECM. The code may illuminate the check engine light and store a freeze frame data, which can help you identify the conditions that triggered the code.

What are the symptoms of a P0277 code?

The symptoms of a P0277 code may vary depending on the severity and duration of the problem, as well as the type of engine and vehicle. Some common symptoms include:

car vertical
  • Illuminated check engine light
  • Reduced power or acceleration
  • Rough idle or stalling
  • Misfire or hesitation
  • Hard starting or no starting
  • Increased fuel consumption or emissions

What are the possible causes of a P0277 code?

The possible causes of a P0277 code are many, but some of the most likely ones are:

  • Failed or clogged fuel injector
  • Open or short circuit in the injector wiring or connector
  • Damaged or corroded injector terminal or pin
  • Failed or damaged ECM or injector driver circuit
  • Low fuel pressure or flow
  • Exhaust gas recirculation (EGR) valve stuck open
  • Carbon buildup in the intake or combustion chamber
  • Vacuum leak or air induction system fault

How to diagnose a P0277 code?

Diagnosing a P0277 code requires some basic tools and skills, as well as a systematic approach. Here are the general steps you can follow:

  • Check for other related codes and freeze frame data
  • Inspect the injector wiring, connector, and terminals for damage, corrosion, or loose connections
  • Test the injector resistance, voltage, and current using a digital multimeter and a noid light
  • Check the fuel pressure and flow using a fuel pressure gauge and a fuel volume tester
  • Inspect the EGR valve and clean or replace it if needed
  • Check the intake and exhaust systems for leaks or restrictions using a smoke machine or a vacuum gauge
  • Perform a compression test or a leak-down test to check the engine’s mechanical condition
  • Use a scan tool or an oscilloscope to monitor the ECM’s signals and outputs

How to fix a P0277 code?

Fixing a P0277 code depends on the actual cause of the problem, but some common repairs are:

  • Replace the faulty injector or clean it using an injector cleaner or a ultrasonic cleaner
  • Repair or replace the damaged wiring, connector, or terminal
  • Replace the damaged ECM or repair the injector driver circuit
  • Replace the fuel pump, filter, or regulator if the fuel pressure is low or erratic
  • Clean the intake and combustion chamber using a top-end cleaner or a carbon cleaner
  • Repair the vacuum leak or air induction system fault
  • Replace the engine if the compression or leak-down test fails

Conclusion: How to prevent and deal with a P0277 code?

Preventing a P0277 code requires some basic maintenance and care, such as using quality fuel, changing the fuel filter regularly, checking the oil and coolant levels, and following the manufacturer’s recommendations. Dealing with a P0277 code requires some patience, skill, and knowledge, but it can be done with the right tools and attitude. By following the steps outlined in this article, you can troubleshoot and fix a P0277 code and enjoy a smooth and reliable ride.


  1. Can a P0277 code cause engine damage?
    No, a P0277 code usually indicates a fault in the fuel system, which can affect performance and emissions, but not necessarily cause engine damage. However, if the code is ignored or left untreated for a long time, it may lead to more serious problems, such as overheating, valve damage, or piston damage.

  2. How much does it cost to fix a P0277 code?
    The cost of fixing a P0277 code depends on many factors, such as the type of vehicle, the severity of the problem, the location of the repair shop, and the parts and labor involved. Generally, you can expect to pay between $100 and $500 for a basic repair, and up to $1000 or more for a complex or extensive repair.

  3. Can I drive with a P0277 code?
    It is not recommended to drive with a P0277 code, as the engine may experience poor performance, misfire, or stalling, which can be dangerous or cause further damage. It is better to have the code diagnosed and fixed as soon as possible, to avoid more serious consequences.

  4. Can a P0277 code be intermittent?
    Yes, a P0277 code can be intermittent, which means that it may come and go, or appear only under certain conditions, such as hot weather, high altitude, or heavy load. This can make the diagnosis and repair more challenging, as you may need to replicate the conditions that trigger the code.

  5. Can I reset a P0277 code without fixing the problem?
    Yes, you can reset a P0277 code using a scan tool or by disconnecting the battery for a few minutes, but this will not fix the underlying problem. The code may come back soon or later, and you may risk damaging other components or affecting the performance and emissions of the engine. It is better to diagnose and fix the problem first, and then clear the code using a scan tool.