P0204 Fault Code

P0204 OBD-II Trouble Code Short Description

Cylinder 4 Injector Circuit Malfunction

What does trouble code P0204 mean?

The P0204 fault code on cars refers to a problem with the fuel injector circuit in cylinder 4. This code is often detected by the car's computer system during an emissions test or when there is a noticeable decrease in engine performance.

The solution to this problem typically involves checking and repairing any damaged or faulty wiring, replacing the fuel injector for cylinder 4, or updating the car's computer software. It is important to address this issue promptly, as driving with a faulty fuel injector can lead to further engine damage and decreased fuel efficiency.

Some possible reasons for the P0204 fault code include a clogged fuel injector, an issue with the fuel supply to cylinder 4, or a problem with the car's computer system. Regular maintenance and inspections can help prevent this issue from occurring, and it is important to address any symptoms of engine trouble promptly to avoid more serious problems down the line.


What are the symptoms of the P0204 code?

The P0204 fault code indicates an issue with the fuel injector circuit in cylinder 4 of a car's engine. This can result in a number of symptoms, including:

  1. Decreased engine performance and acceleration
  2. Rough idling or stalling of the engine
  3. Trouble starting the engine
  4. Reduced fuel efficiency
  5. Engine misfiring or backfiring
  6. The "Check Engine" light may illuminate on the dashboard.

If you are experiencing any of these symptoms, it is important to have the issue diagnosed and repaired by a qualified mechanic to prevent further damage to your vehicle.


What causes the P0204 code?

P0204 is a fault code commonly seen on cars, particularly those with an engine control module (ECM). It indicates a problem with the fuel injector circuit in cylinder 4. Here are the common causes of a P0204 fault code:

  1. Malfunctioning fuel injector - The fuel injector for cylinder 4 could be defective and not operating correctly, leading to a P0204 fault code.

  2. Wiring issues - The wiring in the fuel injector circuit may be damaged, corroded, or shorted, resulting in a P0204 fault code.

  3. Faulty ECM - The engine control module may be at fault and not sending the correct signals to the fuel injector circuit. This can lead to an erroneous P0204 fault code.

  4. Intermittent electrical connection - If the electrical connections in the fuel injector circuit are loose, the signals may not be properly transmitted, leading to a P0204 fault code.

  5. Fuel system problems - Other issues such as low fuel pressure, a clogged fuel filter, or a faulty fuel pump can also cause a P0204 fault code.

It is important to diagnose and fix the underlying problem that is causing the P0204 fault code in order to ensure proper engine performance and prevent further damage. A professional mechanic can properly diagnose and repair the issue.

Possible Solutions

How to fix P0204?

If your car is showing a P0204 fault code, it means that there is an issue with the fuel injector circuit in cylinder 4. Here are some steps you can take to fix this issue:

  1. Check the fuel injector- Start by checking the fuel injector wiring and connections for cylinder 4. Look for any frayed or damaged wires, loose connections, or corrosion.

  2. Test the fuel injector- You can use a multimeter to test the fuel injector's resistance. The resistance should be between 11-18 ohms. If it's not within this range, you may need to replace the fuel injector.

  3. Check the fuel injector fuse- Make sure the fuel injector fuse is intact. If it's blown, replace it with a new one.

  4. Test the fuel injector driver- Use a noid light or oscilloscope to test the fuel injector driver circuit. If the circuit is not working properly, it may need to be replaced.

  5. Check for other issues- Check for any other issues that may be causing the fuel injector circuit to malfunction, such as a faulty ECU or wiring issues in other parts of the car.

In some cases, you may need to replace the fuel injector or other parts of the fuel injection system to fix the P0204 fault code. If you are unsure how to proceed, it's best to take your car to a mechanic to diagnose and fix the issue.


  • What is the meaning of P0204 code?

    P0204 code means that there is a fault in the injector circuit of cylinder 4 in the engine.

  • What are the symptoms of P0204 code?

    Symptoms of P0204 code include rough engine performance, poor acceleration, hesitation, and misfires.

  • What causes P0204 code?

    Common causes of P0204 code include a faulty or clogged fuel injector, wiring issues in the injector circuit, or a malfunctioning PCM.

  • How is P0204 code diagnosed?

    P0204 code can be diagnosed using an OBD-II scanner, which will retrieve the code and provide information on the circuit affected. Further troubleshooting may require a multimeter or oscilloscope to test the components in the circuit.

  • Can driving with P0204 code damage the engine?

    Continuously driving with P0204 code can cause damage to the engine and catalytic converter due to unburnt fuel entering the exhaust system.

  • Can P0204 code be fixed at home?

    Fixing P0204 code usually requires expertise and specialized tools to diagnose and repair the cause of the problem. It is recommended to take the vehicle to a certified mechanic or dealership for repair.

  • How much does it cost to fix P0204 code?

    Cost to fix P0204 code varies depending on the cause of the problem and the make and model of the vehicle. Repairs can range from $100 to $1000 or more.

  • Is P0204 code covered under warranty?

    If the vehicle is still under warranty, P0204 code may be covered by the manufacturer's warranty. It is recommended to check with the dealership or manufacturer for more information.