P0390 Trouble Code: Meaning, Symptoms, Causes & Fixes

The P0390 trouble code technically means "Camshaft Position Sensor 'B' Circuit (Bank 2)". Here's exactly what you need to do to fix it.

P0390 Technical Description

Camshaft Position Sensor ‘B’ Circuit (Bank 2)

If you’re here, you’re likely seeing a P0390 trouble code pop up in your car and are wondering what it means and how to fix it.

This guide will break down everything you need to know, from symptoms to solutions.

Having worked on numerous vehicles with the P0390 code, I’ve seen firsthand how it can affect engine performance.

In this post, we’ll dive into what triggers this specific trouble code, outline the most common symptoms associated with it, and provide practical steps to diagnose and resolve the issue.

Ready to tackle the problem? Let’s get to the heart of the matter.

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Key Takeaways

  • The P0390 code indicates a problem with the camshaft position sensor ‘B’ on Bank 2.
  • Symptoms include rough idling, poor acceleration, and potential engine stalls.
  • Causes range from faulty sensors to wiring issues and mechanical timing faults.
  • Diagnosis should start with a thorough scan and visual inspection.
  • Fixing the issue may involve replacing the sensor, repairing wiring, or adjusting engine timing.
  • Always clear the code post-repair and test drive to confirm the fix.

Table of ContentsShow

What Does P0390 Trouble Code Mean?

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The P0390 trouble code signals an issue with the camshaft position sensor ‘B’ located on engine Bank 2.

Understanding this code requires some basic knowledge of your engine’s layout. In V-shaped engines, Bank 1 is typically the bank containing the first cylinder, and Bank 2 is the opposite side.

The ‘B’ designation refers to the secondary sensor, as these engines often use multiple sensors for better accuracy in monitoring camshaft position.

Why does this matter?

The camshaft position sensor helps regulate the timing of your engine’s valves. It provides data to the engine control module (ECM) about the position of the camshaft, which in turn controls the fuel injection and ignition systems.

Essentially, it ensures your engine runs at peak efficiency, coordinating the opening and closing of valves in sync with the pistons.

When the P0390 code appears, it means the ECM has detected a fault in the electrical circuit of the secondary camshaft position sensor on Bank 2.

This could be due to a faulty sensor, wiring issues, or a more serious mechanical problem within the engine itself.

For drivers, the implications of a P0390 code can be immediate and disruptive. Depending on the severity of the issue, you might notice rough idling, a decrease in engine power, poor acceleration, and in some cases, the engine may fail to start or could stall unexpectedly.

These symptoms arise because the engine struggles to accurately time its internal processes without reliable data from the camshaft position sensor.

In summary, a P0390 trouble code points to potential faults in the camshaft positioning system of Bank 2, impacting engine performance and efficiency.

Immediate attention to this issue is crucial to avoid further complications or potential damage to the engine.

P0390 Trouble Code Symptoms

When the P0390 trouble code is active, you may notice several symptoms that can affect your vehicle’s performance. Here’s a list of common signs to watch for:

  • Rough idling
  • Decreased engine power
  • Poor acceleration
  • Engine misfires
  • Increased fuel consumption
  • The engine may fail to start
  • Engine stalling
  • Check Engine light is on

P0390 Trouble Code Causes

The P0390 trouble code can be triggered by various issues related to the camshaft position sensor and its circuit. Here are the most common causes:

  • Faulty camshaft position sensor
  • Damaged or corroded wiring
  • Poor sensor connection
  • Fault in the sensor’s circuit
  • Timing belt or chain problems
  • Mechanical timing issues
  • Control module issues, like a faulty ECM

How To Fix A P0390 Trouble Code

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Fixing a P0390 trouble code involves several steps to diagnose and rectify the issue. Here’s how to approach it:

1. Scan and Verify

Start by using an OBD-II scanner to confirm the presence of the P0390 code and check for any other related codes. Codes related to other sensors or systems can provide clues about underlying issues.

2. Visual Inspection

Inspect the wiring and connectors leading to the camshaft position sensor for any visible signs of damage like cuts, burns, or frays. Look for signs of corrosion on connectors which can impede proper function.

3. Check the Sensor

Test the camshaft position sensor using a multimeter to ensure it is receiving power and grounding properly. Compare your findings against the manufacturer’s specifications. A faulty sensor will often show no continuity or incorrect voltage.

4. Timing Components

Inspect the timing belt or chain for wear, damage, or misalignment. Issues here can cause the camshaft to operate out of sync, triggering the P0390 code.

5. Replace Faulty Parts

If the camshaft position sensor or any part of its circuit is damaged, replace these components. Always use OEM parts for the best compatibility and reliability.

6. Clear the Code

After repairs, clear the trouble code from the ECM using an OBD-II scanner and take the vehicle for a test drive to ensure that the repair has resolved the issue.

7. Further Diagnosis

If the code reappears after your initial repair, you may need to conduct a more in-depth examination of the ECM and other related systems. Sometimes, persistent issues can be due to deeper electrical problems or even a failing ECM.

Following these steps should help you address a P0390 trouble code effectively, restoring your vehicle’s engine performance and reliability. Always ensure to follow safety guidelines while working on your vehicle and consult a professional mechanic if the problem persists.

Conclusion

You’re now equipped with the knowledge of what a P0390 trouble code means and the steps to fix it.

Have you ever encountered this trouble code before in your vehicle?

Drop a comment below and share your experience or any additional tips you might have for tackling the P0390 code.

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Jeffrey Monahan

Jeffrey is an ASE-certified mechanic, boasting 17 years of dedicated experience in the automotive field. His skill set is broad, with a particular focus on American and Japanese cars. He loves repairing American and Japenese cars in his free time and he uses his hands-on expertise in Trouble Scan to provide the best advice and repair guides for car owners.