What is OBD-II Code P25FD – Turbocharger/Supercharger Bypass Valve C Temperature Too High

What is OBD-II Code P25FD – Turbocharger/Supercharger Bypass Valve C Temperature Too High

Modern automobiles are incredibly complex machines designed to run with pinpoint accuracy. As part of their design, they come fitted with an array of sensors and detectors that monitor various vehicle systems and components for faults or malfunctions. In case any such error is detected, the vehicle’s On-Board Diagnostics system (OBD) illuminates a warning light on the dashboard.

However, sometimes, this warning light on the dashboard is not enough to describe the exact problem. Thus, the OBD system sends a DTC or Diagnostic Trouble Code to the onboard computer. One such OBD-II code is P25FD – Turbocharger/Supercharger Bypass Valve C Temperature Too High. In this article, we will explain in detail what this code signifies and how to resolve the issue.

What is OBD-II Code P25FD?

The OBD system codes are four-digit codes that identify the type of issue that is troubling your vehicle. Code P25FD implies that there is a problem associated with the bypass valve for the turbocharger or supercharger in your vehicle and uses sensor C as a reference point. This often indicates that the temperature is beyond the acceptable level for its functioning. Usually, this code is related to issues with the bypass valve or the malfunction of the control module. It can also be due to a faulty actuator or solenoid in the system.

Understanding the Turbocharger/Supercharger System

To understand the issue better, it is necessary to grasp the functionality of turbocharger/supercharger systems. The turbocharger is a device fitted to a vehicle’s engine that increases the amount of air intake. When the engine “breathes” more air, it can burn more fuel and generate more power. The turbocharger works by compressing and delivering more air to the engine, which enhances its performance. Superchargers use an engine-powered compressor to push more air into the engine.

Both superchargers and turbochargers can add significant amounts of heat to an engine, which is why they typically include a bypass valve. This valve serves to regulate the pressure and temperature within the system to keep it from overheating or sustaining any damage.

What Causes Code P25FD?

Code P25FD could be a result of several probable causes, including:

1. Faulty Supercharger/Turbocharger Bypass Valve – When the bypass valve is not working correctly, the pressure within the system builds up, and the temperature level crosses the threshold, resulting in this error code.

2. Malfunction of Control Module – The bypass valves usually come with a control module that monitors and regulates its functioning. If the control module malfunctions, it may stop the bypass valve from working correctly. The system may then experience a malfunction that triggers an error code.

3. Failed Actuator or Solenoid – The valve actuation is often controlled by a solenoid, and if this solenoid fails, it can affect the entire bypass valve system’s functionality. This may subsequently cause a high temperature in the area surrounding the valve, causing the P25FD error code.

How to Repair the Issue

To resolve this issue, you may need to undertake several steps depending on the cause of the problem:

1. Inspect the Bypass Valve – Begin with a visual inspection of the bypass valve and related components in your vehicle. Look for any visible wear and tear, including broken or damaged valves or hoses.

2. Check Control Module – In case the problem is not evident in the bypass valve, you need to inspect the control module’s working. The module’s function is to monitor and control the bypass valve, and if it malfunctions, it can cause the problem. Consider consulting a professional mechanic to check the control module’s condition and replace it, if necessary.

3. Replacement of Solenoid or Actuator – If it is established that the problem is with the solenoid or actuator, then it is necessary to replace and test these components. Ensure to follow the manufacturer’s guidelines when undertaking this step.

4. Repairing the Wiring – Damage to the wiring within the system can also cause the P25FD error code. Consider doing an electrical test to locate the malfunctioning area and replace or repair the wiring.

5. Replacing the Entire System – In extreme cases where the parts are broken beyond repair, consider replacing the whole bypass valve system.

Frequently Asked Questions (FAQs)

Q. What does P25FD indicate?
A. P25FD is an OBD-II code that signifies an issue with the turbocharger/supercharger bypass valve C temperature being too high.

Q. Can I continue driving my car with the P25FD code?
A. We recommend consulting an expert mechanic to determine the cause of P25FD and its potential impact on your car before continuing to drive.

Q. Will the vehicle’s performance be affected with the P25FD code?
A. If left untreated, the error code P25FD can cause extensive damage to the vehicle’s turbocharger or supercharger system, leading to a performance decline.

Q. How much does it cost to fix P25FD error code?
A. The cost of repair may vary based on the extent of damage, the age of the car, and the component needed. It is best to consult with a professional mechanic to find out the reasonable cost of repair.

Q. Is it possible to prevent P25FD code from displaying on my car?
A. Regular maintenance of the turbocharger or supercharger system helps to prevent the P25FD error code from displaying. Ensure that you follow the recommended maintenance schedule and use high-quality engine oil to reduce heat build-up.


P25FD is a diagnostic trouble code that points to an issue with the turbocharger or supercharger bypass valve’s C temperature being too high. The article has discussed the possible causes and the steps necessary to resolve the issue. Consulting a professional mechanic is the best way to address this issue to prevent further damage to the vehicle and ensure that it continues to operate smoothly. Follow the recommended maintenance schedule to prevent the problem from occurring in the first place and keep your vehicle in pristine condition.

Scroll to Top