P3425 code — how to fix error fast

Modern vehicles use a lot of innovative systems and while that’s often a good thing, it could also lead to OBD2 codes like P3425. The most important thing in these situations is to stay calm and address it immediately with a focus on P3425 code meaning to prevent it from causing further damage.

If you happen to read this code via a diagnostic scanner, there are luckily some ways in which you can properly diagnose the source of it and fix it almost promptly. This is relevant since any postponement will lead to more complications, so follow our guide for detailed instructions.

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What does the P3425 code mean?

The P3425 code is a diagnostic trouble code (DTC) that indicates a fault in the cylinder deactivation system of a vehicle with AFM. This system allows the engine to operate in a fuel-saving mode by deactivating cylinders when they are not needed.

Understanding this code is important because it can affect the performance and fuel efficiency of the vehicle. In this article, we will explain the meaning, causes, and symptoms of the P3425 code, as well as ways to diagnose and fix it.

What causes the P3425 code?

While the root cause of the code can be in the active fuel management itself and cylinder deactivation, there are various reasons that could potentially be behind this code. So, here’s a complete overview of the most common reasons:

Failed or faulty cylinder deactivation solenoid

The cylinder deactivation solenoid is responsible for activating and deactivating the cylinders in the engine. If this solenoid fails or becomes faulty, it can cause the code to appear. Replacing the solenoid is typically the fix for this issue.

Malfunctioning cylinder deactivation sensor

The cylinder deactivation sensor is responsible for monitoring the performance of the cylinder deactivation system. If this sensor malfunctions, it can trigger the code. Replacing the sensor is typically the fix for this issue.

Wiring issues in the cylinder deactivation system

Wiring issues in the cylinder deactivation system can cause the P3425 code to appear. This can include broken or corroded wires, loose connections, or damaged connectors. Repairing or replacing the affected wiring is typically the fix for this issue.

Faulty engine control module (ECM)

The engine control module (ECM) is responsible for monitoring and controlling the operation of the cylinder deactivation system. If the ECM fails or becomes faulty, it can cause the P3425 code to appear. Replacing the ECM is typically the fix for this issue.

Which car models does the P3425 code affect the most?

The P3425 code is most commonly found in General Motors (GM) vehicles equipped with AFM. Some of the models that are most likely to be affected by this code include:

• Chevy Silverado: The cylinder deactivation system in this vehicle has been known to cause issues such as engine misfires and increased oil consumption, which can trigger this code.
• Dodge Charger: Another model that is frequently associated with this code is the Dodge Charger, which is a popular muscle car known for its powerful V8 engine that also suffers from cylinder deactivation technology.
• Dodge RAM: Finally, the RAM 1500 pickup truck is also frequently associated with the P3425 code. This truck, which is made by the same company as the Dodge Charger, has a similar cylinder deactivation system that can cause issues such as engine misfires and reduced power.

How to diagnose the P3425 code

Diagnosing the P3425 code can be a complex process, but there are several steps that can be taken to identify the issue. Here are some diagnostic methods that may be used:

Scan tool diagnosis

Using a scan tool to read the diagnostic trouble codes (DTCs) can be an effective way to diagnose the P3425 code. The scan tool can provide information about the specific issue that is causing the code to appear.

Visual inspection

A visual inspection of the cylinder deactivation system can help identify any obvious issues, such as broken or corroded wires, damaged connectors, or loose connections.

Cylinder deactivation solenoid test

Testing the cylinder deactivation solenoid can help determine if it is functioning properly. This can be done using a multimeter or a scan tool.

Cylinder deactivation sensor test

Testing the cylinder deactivation sensor can help determine if it is functioning properly. This can be done using a multimeter or a scan tool.

How to fix the P3425 code

Once you’ve properly identified the reason behind the code P3425, you can apply one of the following methods to fix it depending on what the diagnostic phase has helped you uncover:

Inspect and replace faulty components

The first step in fixing the P3425 code is to identify and repair any faulty components in the cylinder deactivation system. This might involve replacing a defective solenoid or sensor or repairing damaged wiring or connectors. In some cases, it may be necessary to replace the entire cylinder deactivation system.

Update the engine control module (ECM) software

In some cases, the code may be caused by outdated or incorrect software in the engine control module (ECM). Updating the ECM software can often resolve the issue and restore proper function to the cylinder deactivation system.

Perform a powertrain control module (PCM) reset procedure

A PCM reset procedure can sometimes resolve issues with the cylinder deactivation system by resetting the PCM’s learned values and allowing it to relearn proper function. This procedure typically involves disconnecting the battery for a short period of time, then reconnecting it and allowing the engine to idle for a set amount of time.

Replace the engine control module (ECM)

In some rare cases, the code may be caused by a faulty ECM that cannot be repaired or updated. In this case, it may be necessary to replace the ECM with a new unit in order to resolve the issue.

How to prevent the P3425 code

Preventing the P3425 code can be done through routine maintenance and proper care of the cylinder deactivation system. Here are some preventative measures that can be taken:

• Perform regular cylinder deactivation system maintenance
• Avoid excessive idling
• Having a trained mechanic inspect your car’s AFM system

Having a professional mechanic perform regular maintenance on the cylinder deactivation system can help identify and address potential issues before they become major problems.

Our take

Ultimately, the code P3425 is a common headache for many drivers of vehicles that have the cylinder deactivation system. In these cases, it’s best to address the issue promptly so you can fix the issue at its core and have the code removed, so our team hopes this guide will sufficiently help you with that.