P0262 Cylinder 1 Injector Circuit Low

Why Your Engine Needs Good Fuel Delivery: Understanding Cylinder 1 Injector Circuit Low

If you own a vehicle with a gasoline engine, you may already know that fuel delivery plays a crucial role in its performance and efficiency. The fuel injectors, which are responsible for spraying precise amounts of fuel into the intake manifold or directly into the combustion chamber, need to work properly to ensure a smooth and consistent combustion process. When one or more injectors fail or malfunction, your engine may experience various symptoms, such as rough idling, misfiring, poor acceleration, decreased fuel economy, and increased emissions. One of the trouble codes that may appear on your OBD-II scanner if your engine has a cylinder-specific fuel injector circuit problem is P0262. In this article, we will explain what P0262 means, what causes it, how to diagnose it, and how to fix it.

What is P0262?

P0262 is a generic OBD-II code that indicates a low voltage condition in the fuel injector circuit of cylinder 1. This means that the Engine Control Module (ECM) has detected a voltage signal from the fuel injector that is below the expected range, usually less than 0.5 volts. The ECM uses the voltage signal to control the injector’s opening and closing time, which affects the amount of fuel that enters the cylinder. If the voltage is too low, the injector may not open or stay open long enough to inject the proper amount of fuel, which can cause an imbalance in the air-fuel ratio and a lean condition in the cylinder. A lean condition can lead to overheating, detonation, and other engine damage.

What causes P0262?

There can be several reasons why the fuel injector circuit of cylinder 1 is experiencing a low voltage condition, including:

  • A faulty fuel injector: The injector may be clogged, stuck, or electrically damaged, preventing it from delivering fuel as needed.
  • A wiring problem: The wires that connect the ECM to the injector may be broken, chafed, or corroded, causing a poor connection or a short circuit.
  • A poor ECM ground: The ECM may not be properly grounded, causing a weak or intermittent signal to the injector.
  • A failed ECM: The ECM itself may have a hardware or software defect that affects the fuel injector circuit.

How to diagnose P0262?

To diagnose P0262, you will need an OBD-II scanner that can read live data, freeze frame data, and fault codes. You will also need a multimeter, a wiring diagram for your vehicle, and a basic set of tools. Here are the steps you can follow:

car vertical
  1. Connect the scanner to your vehicle’s OBD-II port and read the fault codes. Note down the code and its freeze frame data, which includes the engine speed, load, coolant temperature, and other parameters at the moment the code was triggered.
  2. Clear the code and start the engine. Monitor the live data of the fuel injector circuit of cylinder 1, which should include the voltage, the pulse width, and the duty cycle of the injector. Compare the data with the specifications of your vehicle’s service manual or a reputable online source.
  3. If the voltage is below 0.5 volts, measure the resistance of the injector with a multimeter. It should be within the range specified by the manual or the manufacturer. If it is out of range, replace the injector. If it is within range, proceed to Step 4.
  4. Check the wiring harness and connectors of the injector circuit of cylinder 1. Look for any signs of damage, corrosion, or looseness. Use the wiring diagram to trace the wires and check their continuity and insulation. Repair or replace any faulty wires or connectors.
  5. Check the ground of the ECM. Locate the ground point of the ECM and check its resistance to the battery negative terminal. It should be less than 1 ohm. If it is higher, clean the ground point and retest. If it remains high, replace the ECM.
  6. Clear the code again and road test the vehicle. Monitor the live data and make sure the voltage, pulse width, and duty cycle of the injector are within the proper range. If they are, the problem is fixed. If not, there may be another issue that needs to be addressed.

How to fix P0262?

To fix P0262, you will need to follow the diagnostic steps we just outlined and replace or repair any faulty components. Depending on the root cause of the problem, you may need to:

  • Replace the fuel injector of cylinder 1.
  • Repair or replace the wiring harness or connectors of the fuel injector circuit of cylinder 1.
  • Clean or replace the ground point of the ECM.
  • Replace the ECM.

Always use OEM or high-quality aftermarket parts and follow the manufacturer’s instructions and safety precautions. If you are not comfortable doing the repairs yourself, seek the help of a certified mechanic or a reputable repair shop.


P0262 is a diagnostic trouble code that indicates a problem with the fuel injector circuit of cylinder 1. It can be caused by various factors, such as a faulty injector, a wiring problem, a poor ECM ground, or a failed ECM. To diagnose and fix P0262, you need to use an OBD-II scanner, a multimeter, a wiring diagram, and some basic tools. By following the diagnostic steps we provided, you can identify the root cause of the problem and repair or replace the faulty components. Remember to always prioritize safety and accuracy when working on your vehicle’s fuel system, and never ignore or reset the warning lights without addressing the underlying issue.


  1. What is a fuel injector?
    A fuel injector is a component of the fuel delivery system that sprays fuel into the combustion chamber or the intake manifold of a gasoline engine. It is electronically controlled by the ECM and operates at high pressure and frequency.
  2. How many fuel injectors does my engine have?
    The number of fuel injectors depends on the design and size of your engine. Most modern engines have one injector per cylinder, while some older engines have one or two injectors for the whole engine.
  3. What causes a fuel injector to fail or malfunction?
    A fuel injector can fail or malfunction due to various factors, such as clogging, leaking, sticking, or electrical damage. It can also be affected by poor fuel quality, low fuel pressure, or excessive heat.
  4. Can I drive my car with a cylinder 1 injector circuit low code?
    You can drive your car with a cylinder 1 injector circuit low code, but it is not recommended as it may cause further damage to your engine and increase your emissions. You should have the problem diagnosed and fixed as soon as possible.
  5. How much does it cost to fix a cylinder 1 injector circuit low code?
    The cost of fixing a cylinder 1 injector circuit low code depends on the root cause of the problem and the labor rates of your mechanic or repair shop. It can range from a few hundred dollars to over a thousand dollars, depending on the severity and complexity of the repair.