P0204: OBD-2 error code interpretation and solutions

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Vehicle engine and/or automatic transmission

Code: P0204 - Injector 4 – circuit malfunction

Code P0204 is a generic diagnostic trouble code that occurs when the PCM/ECM detects an input voltage signal indicating low performance of the fuel injector in cylinder 4. This code is common among various car brands such as BMW, Ford, Mercedes, Toyota, Kia, Renault, Volkswagen, Nissan, Skoda, and others.

Each fuel injector valve is controlled by a solenoid, which allows fuel to exit under pressure. The valve is operated by a special transistor called a "driver," which then moves the valve to the open position. An inactive injector reads nearly the same voltage as the battery, while an active injector drops its voltage almost to zero. If the injector voltage does not match the expected voltage state, the PCM generates code P0204.

Causes of OBD P0204

Common causes of this code include:

Faulty power wires to the fuel injectors
Damaged or disconnected connectors or sockets
A fuel injector that is clogged or filled with debris
Corrosion of the fuel injector, hoses, or connections
An open or short circuit in the wiring for the injector in cylinder 2
A faulty fuel injector in cylinder 4

Symptoms of Error P0204

Symptoms of code P0204 include:

Illuminated Check Engine light
Rough engine operation
Engine stalling
Misfires
Poor fuel efficiency
Reduced engine power (limp mode)
Rich or lean fuel mixture
Difficulty starting the engine

How to Diagnose DTC P0204?

To diagnose code P0204, a technician should:

Scan for codes in the ECM and review freeze-frame data to detect irregularities.
Visually inspect the injector harness and connectors for damage, loose connections, or corroded terminals.
Check fuel pressure and fuel injector spray pattern.
Test the ignition system for misfires.
Perform an engine compression test.
Check for vacuum leaks.
Remove the injector and inspect it for dirt or damage.
Test injector resistance with a multimeter.

Common Mistakes When Dealing with OBD Code P0204

Here are some of the most common mistakes technicians make when diagnosing code P0204:

Failing to fully inspect all wiring and connectors.
Not checking fuel pressure or injector spray pattern.
Ignoring the ignition system when looking for misfires.
Failing to check engine compression.
Overlooking vacuum leaks.
Replacing the injector without verifying if it is actually defective.

How Serious is the P0204 Error?

Code P0204 is considered a serious issue and should be fixed as soon as possible. Ignoring this code can lead to poor engine performance and even cause severe engine damage.

How to Fix Code P0204?

The following solutions may resolve this issue:

Repair or replace any faulty components, such as wires, connectors, or hoses.
Clean or replace the fuel injector if it is clogged or damaged.
Perform an engine compression test.
Test the resistance of the injector coil.
Replace the ECM/PCM if all other repair options have been exhausted.

Conclusion

In conclusion, code P0204 is a diagnostic trouble code indicating a problem with the fuel injector in cylinder 4. There are several possible causes, and the most common ones should be checked first. This code typically leads to poor engine performance and may cause damage if left unresolved. Some possible repair solutions include fixing or replacing faulty components, cleaning or replacing the fuel injector, checking engine compression, and testing injector coil resistance.

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OBD P0204 code analysis and solutions

The page presents a detailed analysis of code P0204 for Opel, Renault, VW (Volkswagen), Ford, Peugeot, Mitsubishi, Skoda, BMW, Citroën, Toyota, Lada, Honda, Kia, and other models to investigate probable causes and solutions related to OBD-2 errors, with main attention on the issue. We offer engineering documentation and methods for diagnostics to identify and overcome the difficulty effectively. We aim to make our resource a comprehensive source of information on issues related to OBD 2 errors, equipping you with the means for effective repair and maintenance of your auto. If during the repair of OBD 2 errors you need to purchase parts, don’t forget to visit Avtopro!